iPhone needs screen replacement?

My Iphone 6 just quit working out of the blue once I upgraded to an 8 and stopped using it for a week. Bought a replacement battery but it didn’t work (probably was a defective battery). Bought a second battery and I got it to turn on, but the screen has werid white lines, see image.

I replaced an iphone 5 battery the first time without any issue, but I didn’t unplug the screen, for this iphone 6 I did unplug the screen.

(1) is there something unplugged that I can fix (not sure if you can tell by the picture)? I tried making sure every thing was secure plugged in. Not sure if I need to retry plugging everything in or if I damaged a cable in the battery replacement process and the screen needs to be replaced

(2) is there a way to hook this up to say a macbook to read the screen without using the iphone’s screen? Just want to get a few pics off the phone and resell it.

(3) screens are fairly cheap on ebay. I think $25 for the whole unit and $15 without the camera and home buttons. Is the repair easy if I buy a screen without the camera/home button and use the camera/home button off my old screen? Or should I just opt for the whole unit that includes a new camera/home button and screen?