A few random questions

So I have got the main game, not HotIS.

Q1) I've been getting some of the salvage crates, and getting things like medium rifles and chem lasers. I thought these were only in HotIS?

Q2) Where do I get ammo for the rifles / chem lasers?

Q3) Are things such as the ECM available in the base game as well?

Q4) Can you find the same hero twice? (i.e. you buy hero mech, later find it on sale again). Seen a few posts, but never got a straight answer)

Thanks to all