2001 Volkswagen Eurovan Trouble codes and emissions issues?

I have a 2001 Eurovan. My check engine light starting coming on sporadically last year. VW dealer told me to change the O2 sensor and air pump. I wanted to wait because it was driving well and I was not sure about paying close to $2k for it. Took it back later for repair and was told nothing wrong (no codes). Couple of months ago, I drove it on a trip after letting it sit for a while. I had to jump start the battery and it began to run rough on trip and believe it had some condensation in tank also EPC and stabilization lights showing in addition to check engine. Once condensation taken care of with new gas and gas treatment, it was ok and lights off (check engine stayed lit). Drove it a good bit last week and on longer trip, starting running rough and again shows EPC light, stabilization light, and check engine light. It is showing lots of codes and they are P0411, P1198, P0300, P0303, P1152, P0101, P1570, and 0532. I just want some ideas about what to expect or tell someone to check because the dealer will tell me to replace everything and they have a hard time thinking beyond just the code. They don't see any other Eurovan's here and use that as an excuse.