What ISO are you using? If it's high, that would account for the noise. I'm not sure about the poster look, but if you oversharpen, you'll get microscopic outlines at edges, which look artificial. In fact, it's one of the things that characterizes prints from digital cameras. You can reduce this by moving the detail slider to the left, and setting the radius at .5. (I'm assuming you're using Lightroom).

Great shot. I kind of like the super-red cardinal.

No, you have to hold the back-focus button.

Digital is so good at higher ISO's, that I think the advantages of fast lenses pretty much disappear, especially if you're talking about telephoto lenses, which are heavy to begin with, and really heavy if they're fast. I'm getting good results at ISO 1600 and even ISO 3200. There's increased noise, but it's barely detectable (I can't tell, looking at 14 x 21 prints which ones are shot at ISO 200 and which at ISO 3200!). And actually, the noise is nothing like what you'd get in increased grain by pushing Tri-X to 1600.

(I'm using a Nikon D850, which, with a 45.7 Mpx sensor, helps considerably at higher ISO's)

As others have noted, the main benefit of a fast lens is shallow depth of field, so you can get nice bokeh if you're shooting images where you want only a shallow field to be sharp, i.e., when you're photographing, say, a flower, and you only want a few petals to be sharp. And the main advantage of a fast lens used to be speed, especially important to journalists working in low-light situations.

Barring that, there are few advantages to a fast lens, especially since today's cameras can produce good images at high ISO's--in other words, in low-light situations, you no longer need a fast lens. Your camera can do the work. It used to be that journalists who used Tri-X at ASA 400 might "push" Tri-X to 800, or even higher. My Nikon D850 works well at ISO 1600--I only start noticing noise at ISO 3200, and it's actually not much noise at all, compared to pushed Tri-X.

A fast lens also costs more, it's heavier (especially in telephotos), and its aperture for maximum sharpness is likely to be f/4 or f/5.6, whereas a slower lens is going to be sharpest at f/8. I generally try to shoot my landscape work at f/8 to f/11. For macro work, it would seem to me that a slower lens, at a smaller aperture, would be preferable.

I use Scott Kelby's books. I prefer them to videos primarily because later on, when I need to find how to do something specific, I can look it up in the book. He has a book on Lightroom. Also, if you happen to subscribe to the online Lightroom, you automatically get Photoshop, and Kelby has a handy book called Photoshop for Users of Lightroom.

I don't know what your age is, or what your medical condition is, but you might be a candidate for cataract surgery. Nowadays, cataract surgery offers the possibility of inserting corrective lenses in the eye. There are various options, but the one that seems to work best (and is most popular) is a correction for infinity. You'll then need glasses for close-up work, but that's easy. After my own cataract surgery, my vision measured 20-15 in each eye, which is the best it's ever been, obviously, better than "normal," which I didn't expect.

A few small dust particles inside a lens won't make a noticeable difference in your photographs, because they aren't in the plane of focus. While cleaning the outside of the lens with a professional wipe and a good solvent is standard procedure, constant rubbing on the outside of the lens can create microscratches, which aren't good, and which are potentially more potentially damaging than dust. The real problem would be dust on your sensor.

AF stands for "auto-focus." AF-S stands for "auto focus with silent wave motors," i.e., the motor is built into the lens. G means the lens does not have an aperture ring, which was standard with manual focus cameras. ED means the lens features extra-low dispersion glass elements. DX means that the lens is designed for an APS-C DX camera (i.e., it's not for a full-frame camera).

Moonrise over Hernandez was also a badly underexposed negative, which Adams had to intensify to print. He saw the sunlight on the crosses, quickly set up his camera, didn't have time to find the light meter, but instead estimated the exposure based on his knowledge of the luminance of the moon. It should be humbling to all of us to recognize that this great technician actually missed on the exposure of one of his most famous prints.

Very good, and original. What software are you using to process b&w??

There's a tiny switch on the memory card that locks the card. In the future, should this happen, all you have to do is find that switch and turn it on.

I recently had a 24 x 36 aluminum print made for me by Bay City Labs. A bit pricey, but the result was spectacular. And there was no cropping whatsoever. I've also had Bay City do 16 x 24 acrylic prints--again, no cropping. I got what I sent.

Some very good answers here about what's required in the original image to produce a larger image at 300 dpi. You also have to consider how far away you intend people to be when viewing the image. Obviously, a billboard doesn't have to be 300 dpi, for instance. Then, of course, you could have an image that most people would see from a distance of ten feet, which wouldn't require 300 dpi, but if some of them then went up close to look at the image, well, you get the picture.

You already have all the lenses you need. If you need go travel light and pick one lens, I'd go with the 24-70mm. Another thing to consider is what lens looks "normal" to you, i.e., which focal length do you automatically gravitate toward. For many photographers, 50mm is normal, which is why, for so long, it was the lens supplied on 35mm film cameras. Personally, I think 35mm is normal, but 24mm great for landscapes, but this is just me. I'd suggest you go through some of your landscape photographs that you took with your zoom and study the metadata to find out what focal length you actually use most often. My bet is that it will be between 24mm and 35mm, but that's just a guess.