- The hanger is definitely not bent, it is the removable kind and it was removed for shipping, but I checked anyway and it looks fine.

- Both the hanger and frame are aluminum.

- Yes, the cables are Teflon coated - Edit: oh wait, I made a mistake, the cables are not Shimano XTR! They're the cheaper type: Shimano SIS40. I meant to buy XTR but I missed the sale. I wonder if these cables are not that good and not coated? Should I consider better shifter cable for the RD?

- I adjusted the RD and screws according to this video: http://bicycletutor.com/adjust-rear-derailleur/ and shifting was great right after that but the weather was warm then.

How do I know if the chain tension is right? After installing the chain it was definitely too lose/long: with the chain on the smallest gears the RD would go back all the way and would no longer tension the chain. Without any proper measurements I removed 4 links from the chain and it "seemed" fine. But is this something that I might have done wrong? It's definitely not lose anymore and I only have two larger chainrings so the chain is tensioned all the time IMHO. Is it possible it's still too lose?

Edit: Oh no, the RD isn't gunky, not sure how I made that impression. I use thin lube, nothing sticky/greasy on the drivetrain and wipe the chain, cogs and RD after each messy ride or at least once every few days and re-apply a small amount of lube to the inside of the chain.

I use this lube on the drivetrain: http://tinyurl.com/yfn2olk. I apply it the day before and let it dry.

Adam