Shawn B

Just use a pair of needle nose pliers to hold the nut in place. You can even try to hold the nut in place just by putting some pressure on it with your finger as you try to unscrew it.

Thats called a nut, and due to its location, you should just be able to loosen it up by trying to loosen the screw thats on the other side of the video card

The bottlenet will come from your CPU as it is only a 3rd gen i5 with only 12 gigs of ram

Shouldn't be a problem. Just as long as you have a PCIe socket for it

Check in your BIOS and make sure that the M.2 Drive is not setup as a removable hard drive.

It sounds like the lightening strike took out your Ethernet port. I would suggest you find if your computer can accept a network card. If so, just get one of those. Thats if Hiya! advice doesn't help you out.

I currently own a Tevo Black Widow. Its a little above your $400 range, and its build volume, its currently 370x250x300. All in all, its a very solid printer. But if you really want to buy the very best 3D printer, just get a Prusa MK3. Its the cream of the crop when it comes to Consumer 3D Printers. They are a bit pricey, but they are totally worth it.

Yup, those are for an external water cooling setup system. Just in case the case itself didn't have enough room for all your water cooling needs. This is exactly why I have a Full Tower Case. It gives me plenty of room for whatever may arise.