Viewing targets on a PC would simply be setting up a bunch of overlaying HUDs and working them into a nicely laid "GUI" for the user to see and use.
Of course, this is going to go differently and you'll have different benefits depending on which version of FPSC you use.
Are you planning on having the player return to the house after each mission? If so, then I'd be more concerned about how you're going to pull that off, if I were you.
As of right now, there's no way to do that without a Mod.
I'm not exactly sure what you're trying to ask with #2. Once you get a weapon, the player keeps that weapon until he/she starts a new game. It doesn't change when the player goes to new levels. (Not from my experience anyway)
The one and only,