Canon T7i for product photography?

I have an old Canon XT that I've had since new, and which I've probably taken several hundred thousand photographs with. It's finally wearing out, it is very clunky to upload to windows, and it's long past time to upgrade.

I have a website and eBay store where I sell collectibles, mostly vintage Barbie and action figures. Some of the accessories I photograph are very tiny -- it's not too unusual for a fingernail sized shoe or weapon or random bit of colorful plastic to be worth $$.

I shoot with a light box, for the most part, though sometimes I use a fill flash for bigger items or large lots, and daylight. (I should note I've got quite a bit of "old school" 35mm experience. I grew up in a house with a purpose built darkroom, and I still have my old Minolta SRTs around and occasionally drag them out for fun.)

I'm eyeing the Canon T7i but I had some questions about it.

1) I'm liking the idea of being able to view and upload images and adjust settings live via wifi from my laptop, but how efficient is this really? Also, does the camera need a wifi router or is it directly beaming to the laptop? (If it has to talk to our wifi router first, that could be an issue due to the distance between the router and camera. I have a wireless printer that will not work in my office because it's too far from the router,)

Also, how easy/practical is this app to use?

I can always use a cable, but that's one more cable to trip over in tight quarters, or forget it's attached when I pick up the laptop. (CRASH has happened more than once with peripherals if I'm distracted by something.) And frankly, with the volume of photographs I shoot, if I'm constantly hooking a cable up, that's one more thing to wear out.*

2) Am I correct in thinking that the lenses for my XT should work with t7I but I'll need to get new spare batteries and flash cards?

3) Has there been any significant improvement in lens quality since around 2005? I have no real complaints about the lenses I have (they're all canon) other than that I don't have a macro with a really small aperture for deep depth of field. (It's not in the budget right now, but I'd welcome suggestions for a good macro for shooting very small subjects -- think Barbie shoes -- because I will eventually need to upgrade since my lenses. They've got the same amount of use as the camera body.)

4) How friendly is the PC based user interface for someone with crappy vision? One of the reasons for looking for a new camera is that I just can't see the dials and buttons easily any more, If I could adjust the settings from my PC that would make life MUCH easier.

Side note, on the XT -- I am astonished by how well that Canon XT has held up. I got it in December 2005 and have used it continuously since. The paint's worn off some of the buttons, and my hand print is visible on the grip, but it more-or-less works at higher shutter speeds.

Lately I've noticed some randomly occurring image blurriness at slower shutter speeds that I suspect is mechanical in nature, because of camera shake from mechanical parts that are quite simply wearing out. It's had a LOT of use LOL.

This means I'm shooting at higher shutter speeds to compensate, which means I have problems with exposure even in the light box for dark widgets, and my black background is getting pretty noisy. I don't have time nor inclination to do extensive editing in photoshop, either, to fix issues.

Below are some photos I took last weekend, to give you guys an idea of what I an photographing, and the issues I'm now having because if needing to use higher shutter speeds.

(ISO 100 is my default ISO for shooting this stuff because it's pretty noisy at higher ISOs when I crop the photos. I don't remember having that much noise when the camera was new, so it may be age related or just something I'm doing, but it makes for ugly photos.)

Need new camera LOLOLOL!