RUG is a matchup where you NEVER board out Library. Filtering for card quality is something you desperately want in this matchup. Even if you're only using it as a Mirri's Guile, that's perfectly fine. You having access to the good cards when you need them is essential.
My board plans for RUG are:
on the play:
-3 Pulse
-1 Garruk
(Loam is already in the main)
-2 Thoughtseize
+2 Choke
+2 Timely
+2 Pernicious Deed
Deed isn't 100% necessary, since I've got 2 Engineered Explosives main, but otherwise, it seems fine. Deed on the draw might be clunky, though.
For your thing, I'd take out all the Pulses and keep the Library. Keep the Pridemage since you need creature density and can win Goyf wars.
-Matt