Correct on the 90 elbow, simple fix.
TDI Club sensors anything emissions related because they're worried someone is gonna come after them or something, oh well.
Dynamic EGR is a nice feature. If I still had a good working EGR, I'd run it in my car(I'm a Malone Dealer) but if your EGR is already crapping out, just get rid of it. Not worth the hassle of replacing an expensive piece of equipment.
Leave the EGR valve/ASV in place unless the ASV takes a dump too.
Stage 1.5 is as far as you want to go on the stock turbo, its always a good idea to log or at least have a boost gauge and verify your turbo is responding correctly - old sooted up vanes sometimes get sticky and it'll spike or overboost.