Is it possible to do this? I've never really fiddled with modding much but I was playing around with the functions of VATS and made a couple of simple little mods for myself just for testing; One is no bonus crit chance in VATS and the other is 100% crit bonus chance in VATS. However I don't know how to visually change VATS to make it hide the hit chance percentages, if that's even possible. I've looked around for mods and can't find anything like that but would be more than happy to do it myself if I had an inkling how.

This requires some XML editing or alternatively some FOSE/NVSE scripting to modify XML values on the fly. Either way, the first steps involve finding the XML file that defines the VATS menu and finding the values that you want to change inside. You'll find the vanilla file packed inside the Fallout - Misc.bsa archive (same location for FO3 and FNV.)

The XML schema used for menus in TESIV/FO3/FNV has a fairly steep learning curve and documentation is very sparse, but this sounds like a simple enough project for someone getting into it for the first time. This is a good reference for beginners: http://www.loverslab.com/topic/53411-reading-ui-hud-xml-files/

Wow thank you very much for the information! I'll try it out.