Personally for me I feel the relic powers are good enough, in fact the +1 power one felt slightly overpowered, as the difference between using 1 stam to dig vs 2 stam literally meant doubling your stamina. Please dont make the powers even stronger, unless we have new layers with harder difficulty.
Also, I think Teaminds meant he would like to have Steam achievements, and as far as I know, Steam achievements dont provide any "usable" bonuses like what you mentioned