First, the rounds aren't stripping aluminum off the mags, the mag lips or feed ramp are stripping lead off the bullet. Think about it - which is softer?

Second, you might have to tweak the magazine feed lips a little with a pair of needle nose pliers so that the nose of the bullets sit up a little higher to fix the feeding issue. It's a common issue with both the 64's and the old single-stack bolt-action magazines. Yes the mag's are crap, that's why they have come out with a new semi-auto design with rotary magazines in recent years.

On the ejection issue, if you're getting stove pipes (spent case not clearing before bolt closes) that's usually a sign of it needing a thorough cleaning. Make sure to scrub the breech face and bolt face with a nylong brush and some solvent to remove any built up residue from the extractors and extractor slots.