It is manufactured in China.
Yes, the Bushnell Prime 1-4x32 Rifle Scope will function as intended mounted to an AR15. I would recommend using a 1-piece mount like the Aero Precision Ultralight 1in Extended Scope Mount, found by using the link below:
https://www.opticsplanet.com/aero-precision-ultralight-scope-mount-extended.html
When mounting optics on the AK platform, you typically want the optic to be as low as possible to the rail for a better head position when utilizing your optic. Based on the objective lens size (32mm), I would recommend medium height rings for this particular scope on the AK platform. That's if you have a picatinny rail located on the top cover itself. If you are using a side mounted scope mount, low height rings should work fine.
Please contact the manufacturer for that information. https://www.bushnell.com/bushnell-footer-assets/bu-contact-us.html
This does have a short integrated throw lever. Because of the integrated lever, getting an extended lever that will fit on there properly may prove very difficult to find. One of these may work, but you will need to measure the diameter of the magnification ring using a caliper to see which one might fit.
https://www.opticsplanet.com/switchview-magnification-adjustment-throw-lever.html
Yes this can take the recoil of 450 bushmaster.
Yes, it will.