Well, fixing unobtainable achievements is pretty easy, there is just need to change them a little. Would work perfect if;
-Miner achievements would be changed from "deposit X minerals into gate" to "collect X minerals". It would keep the sense and allow it to be gained at the same rule as before.
-Walk it off achievement would be changed to "revive teammates X (5, 10) times" or "revive teammate when you are dead", etc. I'm not really sure about that one, but this seems to be only option with some sense.
Idea mostly concerns at Steam achievents, because old achievements are not allow SK to get 100%.
Isn't this sorta a clone of that thread that got locked?