#1
Well, the question is in the title.

I'm using Riffworks T4, but I'm not really a huge fan of it. A friend of mine says that Sony Acid recording software is decent for it's price, but the only recording equipment I own is a Stealth Plug.

Just curious whether or not the Stealth with work with Sony Acid.
#2
if the stealth plug is asio4all compatible then you should be fine. i personally use acid for most all my music that uses actual guitars and i really enjoy the interface, i find it easy to use and a bit underrated when people ask "what DAW should i get"

check out reaper also if you haven't, it's free and is quite good as well.