Any chance that Highlight Tone Priority is set on. If so then 100 ISO is not selectable. You should be able to tell if it is on by looking at your screen when in normal information mode. If there is a "D+" under the ISO symbol then it's on. The setting can be found under Menu > First Camera symbol > third screen (of five).

Back button Focus will seem really awkward at first. Just keep at it for a while and soon you'll wonder why you didn't try it sooner. If you hand your camera to someone not use to it, their pictures may be hit or miss.

The EFS and EF lens are already marked. EFS lenses from Canon have a white alignment dot and EF lenes have a red alignment dot. Third party Canon lenses tend to follow the same standard.

I keep one year's worth of photos on my main computer (a laptop with a reasonable sized hard drive). At the end of the year I move that year's photos to an external USB drive within Lightroom. The catalog stays on the laptop. I mirror/copy the USB drive to an identical drive and store that one in my office at work. Daily incremental updates are done to a network attached system. The external USB drive is also copied to the NAS as well. Still looking for a good way to get a third copy on the laptop photos to an offsite system other than using an online service. Possibly another External HD for just the current year that goes back and forth from home to office as needed.

Two things come to mind (although you say nothing changed in the menu). I'm sure they seem overly simple, but you never know based on my own experiences. The previous suggestion was probably the most obvious.
1. Is the camera actually taking an exposure when you fully press the shutter? If not then the problem is the camera and not the flashes.
2. Is it possible that the external flash might have been disabled in the flash menu. I did that one once accidentally.

I made a couple of these and they work pretty well. I think I spent about $6 on the two of them.
http://super.nova.org/DPR/DIY01/

Zenfolio offers a wide array of products and several print labs. Not a free alternative, but it works well. Look around the web and you might find a discount coupon for the first year.

www.zenfolio.com

I have been quite pleased with the Yongnou YN-622 system. I also use the YN-602 triggers as well, but these are fairly dated now although they still work well as a shutter release.

I find Lightroom to be just the ticket for the kinds of work that I do a lot of ... gymnasium colorguard/dance competitions/performances. I might shoot 1000 (or more) pictures in an evening. If I missed getting the white balance right when shooting, I select all of the pictures and fix the WB on one and all are updated. The same goes for exposure, contrast, sharpening, lens correction, adding a subtle vignette, etc. I don't think that PS and Bridge is so good at this sort of batch work, but I might be wrong since I don't use that combination. I can export from raw to jpg direct to a hosting site from LR as well. I find LR to be pretty easy to use once you figure out what the develop sliders do and you can work through a mass of performance (or wedding reception) pictures quickly marking the good and ones rejecting the bad ones in one pass. Sometimes having done some simple batch correction first can ge very helpful as you go through an evening's group of pictures.

Yes it was the 568exii. This is the first piece of Yongnuo kit that I haven't been happy with. I hope it was the particular unit that I received.

I have a number of Yongnuo flashes and agree that the main difference between the two is the lack of HSS on the 565. Also, the 568 does not have a external power port or a standard PC sync port. It does have a 1/8" plug port for sync (possibly an improvement on port types). I have had both units and do not think the 568 is made as well as the 565 (although it might just be the unit that I have). My 568 burned out on Christmas day (purchased in May 2014) and I chose to get another 565 instead. I find that if I need HSS I use my Canon 568exii so HSS is not that important for the YN flashes. I sent an email to Yongnuo about the YN-568 and am interested to see if they respond.

I have five ... make that four ... Yongnou flashes. The newest one, a 568exii, abruptly died on Christmas. This is the first bit of Yongnou kit that I have had stop working. I also have a set of 602 receivers and transmitters and a set of six 622c units. I have been very happy with the YN's for the most part. From the beginning I was less than thrilled with the 568exii unit. For some reason it just did not seem to be as well made as all of the rest on them (468, 560ii, 560iii, 565ex). I am replacing the failed unit with a 565exii. One failed unit has not soured me on the YNs. Hopefully the next one will be as solid as the ones that are still working. I've had the 468 for about 4 years.

I use these as well on the left side of the camera for several years now. They are very strong and hold the camera in the manner intended. If I have a lens with a collar mounting (i.e., 70-200), I use that instead of the camera mount point.

I suggest finding and using the Adobe Raw to DNG converter program and run the Raw file through that. I believe this should work, but I am not certain.

PSP has capabilities that are not available in LR, primarily in the area of layers. I find it a useful addition to LR as you can link to it from LR and if you use the standard Photoshop format (PSD) any edits will be viewable in LR. I have never cared for the organizer module since I use LR. I will probably move away from PSP when LR 6 comes out if Adobe still offers the $10/month deal for LR and Photoshop.