1) Other than handloads Federal Gold Medal Match(FGMM), choose your flavor 168gr or 175gr, if you're shooting 600 yards and under 168 gr do just fine, 175gr for further out. Before the madness you could pick this stuff up on sale for $19/per box of 20.
2) I'm sure there exists some questionable surplus stuff.
3) No, its pretty dirty though. It wont wear out your extractor, chamber, etc. If you don't plan on doing mag dumps where the gun becomes to hot to hold you'll be fine.
My advice get into handloading when components hit the market again, you produce stuff that will blow FGMM out of the water for half the price.