As I understand it:
1: NW upgrade at time of reservation is available on full fare economy for PE. Other economy tickets are thrown into the EAU (EUA?) system, again only for PE.
2: The "most direct" routing costs 40000 for a return upgrade but if you choose an alternative routing they may try to charge you more. e.g. AMS-DTW-SEA might cost you 40000+20000 for a roundtrip upgrade because there is a direct AMS-SEA flight. Agents are giving different answers to this question at the moment so the "say thank you and hit redial" rule applies
3: Dunno. Should be elegible to go onto the automatic upgrade waiting list in any case.
-- Dambus