You seem to have a lot of little things that might be easy to fix, or require some real work.
I really need to get the shakes figured out. It’s really hard to describe as it’s not super rhythmic but like something is either out of balance sometimes or worn out suspension bushings like I can feel every little imperfection. What I can say, it is not cured with speed. Over 75mph it is always there and only gets worse when you hit 85.
This could be tires, wheels, gunk in wheels, or missing wheel weights. Start by looking for bulges in the tires and slipped belts that have made them go out of round. This can be done with them on the car, just jack it up and rotate them for the out of round, and poke your head behind them for the bulges. Please be safe when doing this. You can also remove them for a closer look at bulges.
I replaced the u-joints which did cure the growl over 70mph but caused a growl when over 75 and not on throttle. So it is possible the driveshaft is fucked because I struggle with things like u-joints and bearing installs.
If it has a growl, there is still something wrong with a bearing, or the slip yoke on the trans. You will notice movement without much effort if it is the slip yoke. If it is the pinion bearing on the rear diff, it may take some pressure to move it. Just use a pry bar if it is needed. Also, when was the fluid last checked or changed in it?
if it is the pinion bearing, you might as well have new bearings and seals put in the ends too. It will already be apart, so now is the time to do it.
Meanwhile, I do shocks which admittedly has been ok except for the rear passenger blowing out every time I lower it off the jack despite being gentle.
Please define blowing out?
Front calipers were changed after seizing one but I had trouble getting the crush washers to seal and I probably should have replaced the flex hoses. I did replace rotors as you should, but those are the “pick bearings in” type and I always feel like I do this wrong. Which I am guessing could be part of this shake issue. I tried doing rear drums but had such a problem with that it’s made me hate this car ever since. That job made me feel so insufficient in auto repair.
Okay, when you have the car up checking the tires for out of round, see if there is any play that you can notice. Use a straight edge taped to the tire and a jackstand, or some other stationary object to see if you can notice any movement. The bearings should be "loose" enough to turn the rotors by hand, but tight enough not to have any play noticeable.
I have a hitch receiver on the back but I am scared to use it for anything heavy as it’s held in by grade 8 bolts but I have no washers to spread out to force and the holes for mounting are shall we say, *just* enough to grab toe bolt edge that I really don’t want to use it until that’s fixed. I don’t know how to fix that as a whole hitch receiver kit has the correct wires to pull bolts through a washer, but not available separately.
I would need to see a pic.
At the moment, the front windshield leaks on the drivers side and drips right on the power windows switch. The rear window leaks from decayed weather stripping and is very wobbly from the rear tailgate being taken apart by the PO to replace the window motor. I also found out recently why half the rear window won’t defog...
I only tried to remove one windshield in my life. It ended badly, I was frustrated to no end, and I learned a lesson. It is okay to call a professional.
The defroster can be repaired using a kit that bridges the gaps in the wires. You do need to have a look inside the tailgate to see if something in there is ribbing on it though.
And oh by the way, the starter either needs a new positive wiring and connector, or the whole starter is jacked because hot starts sound like the battery is weak, it’s not because I replaced it February 2019.
Check both ends of the cables to see if there is any visible corrosion that can be cleaned, or if it will just need to be replaced. Beyond that, it could be the solenoid, or the starter. They don't last forever.
I have wheels on from
@CraigB and some boring Uniroyal tires which are very nice however the front bearing dust covers stick out so far that I can’t use the center caps. According to the tire shop, I would need 5/16” wheel spacers which means the lug nuts are not long enough, I tried. Since the studs are built onto the brake rotor, I don’t think it’s smart to do any sort of longer studs or spacers with studs on them.
Why not get a deeper center cap? There must be one available for your car. Are the wheels meant for that car, or do they just happen to fit?
Beyond that, it is possible to install longer studs. An old school parts store would be able to set you right up with what you need, or a good shop can do it.