As long as it's a rail mount, yes it will fit.
This is a standard red dot and has no fixed eye relief.
It comes with two mount height adjustment pieces to find the proper fit for your firearm.
The major difference is that the ARII has a much better battery life at 50,000 while the ARI has up to 300 hours on highest setting and up to 5,000 hours on lowest setting.
The item offered on this product page is a red dot sight. The only item listed anywhere on this product page for $199.00 is a magnifier. The two sights listed on this page only have a difference in color between Black or Tan.
Yes, you can.
Yes, the mount is an absolute co-witness height and includes a lower 1/3 co-witness spacer.
Yes, the sight will work with your KelTec KSG 12.
It strong enough to work with.
If you mean recoil, so, it will hold enough.
As I can see your Ruger 22/45Mark IV has a Weaver plate, so, it will work with SPORC 100%.
Thank You.