Play the Catalan! For Amateurs

Hey y'all,

So the Catalan is a fearsome weapon of many a high-rated player including a fair number of super-GMs we all wish we could be.  I am looking to delve into the White side of this opening and start working towards a full 1. d4 repetoire, something I switched to in the last few months after years of strict 1. e4.

First up, the oddball replies to our move order of choice 1. d4 Nf6 2. c4 e6 3. g3 d5 4. Bg2