Photoshop, like Lightroom, does not modify the RAW file, and it won't modify an original workfile unless you save

The Fuji X100s have leaf shutters.

Theoretically, the APSC image can be quite a bit sharper for two reasons: First, as you pointed out, the APSC is using the best part of most lenses - the central area; and second, the APSC is giving you the full 24 Mpxls in the crop area, whereas the 24 Mpxl full-frame is only giving you about 10 Mpxls in the same crop area with the same lens.

I have the X-T1 and 18-135, and the X-T1 is by far my favorite digital camera ever. The 18-135 is a great do-it-all lens - however, it is large, bulky and indiscrete - so it isn't my favorite. The 18-135 was the last (of 8) Fujinon lenses that I have acquired so far. Since I have a strong preference for the wide-view (and zooms), my most-used lenses are the 18-55 and the 10-24.

If I was starting over with a limited budget, I would probably start with the 10-24 and the 18-135 because those two lenses cover 99% of the focal lengths that I have ever used for the last 50 years. If you don't care about extreme wide angle, then the 18-135 would be an excellent single lens choice, unless you are a "bokeh" fiend, in which case only very fast primes will do.

Yes, old manual lenses labeled "Preset" have 2 aperture rings - the main ring sets the shooting aperture, the other ring overrides the aperture setting and opens the aperture all the way for accurate focus. Once focus is achieved, the photographer turns the preset ring back until it stops, which will bring the aperture back to the shooting aperture without the photographer having to take his eye away from the viewfinder to recheck the aperture setting.

I have been doing real estate and architectural photography for a very long time and have seldom used an aperture below 5.6. You don't need a super fast lens for real estate - you need a lot of depth of field for that, and should be shooting on a tripod at smaller apertures such as f8 most of the time. Huge apertures and shallow depth of field are not the answer for this kind of work.

The 12-24 f/4 Nikkor has been my main "workhorse" lens for years. I have used it very successfully with first a D70, then a D200, D700, and D800. I now use it mostly with a Fuji XT1 with an adapter. The only other lens I use quite a bit is a 24 f/3.5 Tilt-Shift lens when it is desirable to do 2 or 3 shot "panos" using the shift function to minimize wide angle distortion in tight quarters. Unfortunately, the Tilt-Shift only works on the Nikon, which I avoid using these days 'cause I just love shooting with the XT1.

When there isn't enough natural or ambient light, I use flash (sometimes several) or strategically located continuous lighting. I have a box of 5000K CFLs that I install in room fixtures when possible so I can balance the indoor light with what is coming through the windows. I also set the exposure for the windows so they don't get blown out when I shoot with flash.

Back to the lens: If you are shooting with a Nikon 1.5 "crop" camera, that 12-24 gives you a 35mm equiv of 18-36mm, which is just about a perfect range for architecture. And the other great thing about it is that it still gives you a 100% usable range of 18-24mm on a FF Nikon at any aperture with little to no vignetting. And I have used mine all the way down to 15-16mm in a pinch.

I have a Genustech 77mm 2-8 stop "Fader Filter" - $192.50 at B&H today. I have used it extensively with a variety of lenses with and without stop down rings, and am very happy with the results - no problems with sticking threads and no noticeable "color casts" either - I don't care that it is "Just two polarizers put together" - it works as advertised.

Does your Canon have a magnified Live View that you could use when focusing manually? I use manual focus almost exclusively with my D800, and the live-view magnified focus assist is probably my favorite feature.

I get excellent results with 35mm scans from my Epson V750 using the Epson software. I have a genuine 35mm scanner moldering away in the junk room that doesn't do nearly as good.

The Selphy CP910 is a dye sublimation printer. It makes prints in a 4-pass process - 3 to lay down the 3 primary colors, and 1 more for a tough plastic protective coating, resulting in a very rugged print. I dare you to try tearing one up! I have been using the CP910 for about the last 6 months, mostly for proof prints. It prints on 5-3/4 x 3-7/8" glossy paper. The color and print quality are excellent - I highly recommend it if you can live with the size. The print cost is about $30 or so for a box of 108 sheets of glossy paper and the ink "ribbon" to go with the paper. That works out to 28 cents per print.

I like it so much I am seriously considering the purchase of a much larger, faster version (not Canon) that is made for on-site printing at events. These are ruggedized work-horse printers that can print from 4x6 up to 8x12. Check them out here: http://www.imagingspectrum.com/dnp-ds40-dye-sub_printer-ds40.html
The link is for a printer that does up to 6x9". The same company also has a larger one that prints up to 8x12"

Nikon made a series of shift only PC lenses in focal lengths of 28, 35 and 85mm that were were introduced between 1962 and 1999. These were all fully manual lenses.
In 2008, a new series of PC-E lenses were released in 24, 45, and 85mm focal lengths - these have electronically controlled apertures and are Tilt-Shift lenses. I have the 24mm, and have used it extensively for architectural and landscape work, mostly shift panoramas. It is one of my favorite lenses.

I have had Fuji X cameras since the beginning, starting with the X100, then the X-Pro1, and now the XT1. I love them all for different reasons, and rarely take the D800 out of the bag since I got the XT1. I started with the 3 primes (18,35,60mm) when I got the X-Pro1. Then, since I have always been partial to zooms, got the 18-55 the minute it was available. Likewise, the 18-135. They are both remarkable zooms, but the range of the 18-135 makes me leave it on the camera 90% of the time. I really like the compactness of the 18-55, but it just a little short a lot of the time, and the camera fits my everyday small Domke bag with the 18-135 attached, so I really have no reason to use the 18-55 anymore. The only other lens that I usually take with me in that bag is my 12-24/f4 Nikkor, which I use with an adapter for the extra wide shots (architectural interiors, single shot panoramas). I use a 55/1.2 Nikkor with an adapter for those special occasion portraits with nice blurry backgrounds. And last, but not least, I have a Nikkor 50-300/f4.5 for the long-range shots of birds and alligators in the swamps that we love to visit. If someone would come up with a wide-angle tilt-shift lens for the X system, I would definitely sell my D800 kit.

I stand by my statement - I didn't claim that mirrorless cameras currently have all of the capabilities or features of high-end DSLRs. What I meant is that any of the mirrorless camera makers could at any time make a camera that would exactly duplicate all of the functions and features of any Pro DSLR (except for the flippy mirror and through-the lens optical finder that the mirror makes possible).

Fortunately, they aren't just trying to copy DSLR tech. Rather, they are doing their own thing and advancing camera technology to new highs, exemplified in the already excellent EVFs and combined phase and contrast focus on the image sensors, which provides more accurate and in some cases, faster autofocus than DSLRs - and this is just for starters.

I sincerely believe that advancing technology is in the final stages of making DSLRs irrelevant - Canon and Nikon (and a lot of photographers) just haven't accepted the inevitable yet.
For example, have you had a serious look at the on-chip phase detect system in the Sony A6000? It has phase detect sensors covering over 90% of the image sensor, which results in continuous tracking auto focus that is superior to most DSLRs. You can read Gordon Laing's excellent A6000 review summary here: http://www.cameralabs.com/reviews/Sony_Alpha_A6000/verdict.shtml

The E-M10 is not a DSLR, nor are any of its MFT brethren, or any of the modern Fujis. A flipping mirror and optical viewfinder is what defines a film SLR and/or a Digital SLR (DSLR). And, to clear up another misconception about DSLR vs "mirrorless" cameras, there is nothing inherent in SLR technology that makes them superior to "mirrorless" cameras. Canon & Nikon rely on the camera buying public's general lack of awareness of that basic fact to maintain their massive dominance in high-end camera sales, especially in the U.S. I am really looking forward to the time, which I think is finally coming, when camera buyers become enlightened and put an end to the Canikon domination of the market.