BM vs MM after KMST updates

Macro'ing strafe -> snipe -> strafe makes this irrelevant, doesn't it?

No, it doesn't. It just makes it so instead of having to time your transition from Strafe to Snipe and back, you have to time your transition from Strafe to the macro and back.

Unless macroing Strafe -> Snipe will result in spamming Strafe if Snipe is in cooldown?

I haven't tried, the shortest cooldown skill I've ever had is Nimble Feet. I do have that macro'd to 60-second Booster and it collapses nicely when Nimble isn't available, but I've never tried spamming it.