I have two gmail accounts, think of them as "work" and "play". The phone is registered on the "work" one, but most of the mail I get on the "play" one. Is it possible to add both of them to the gmail app but have the phone pull contacts and everything else only from the "work" one, that is only use the "play" one for reading mail?
When you add the account through the gmail app, you will enter your account info, it will verify the info, and then ask you what you'd like to sync, if anything at all. If you don't want anything to sync from the account, then nothing will be. If you change your mind, you can go into the settings -> accounts and sync, and the change it up.
Yes (if I understand you correctly). Just go into Settings - Accounts and Sync, then modify what things are synced per account. In other words, email@example.com can be set to sync gmail, contacts, calendar, etc. But you can set firstname.lastname@example.org to just sync gmail (not contacts, etc). There are checkboxes once you add the account.