1) swap file is easier to make, resize, remove - I dunno. They're rarely used. Partition has faster access thana file for some arcane reason, I think, but mainly helps with fragmentation. It's the usual.
2) Depends on what the fat is used for and what you want it to be like when you're done. Could just delete it, recreate a smaller fat, and a swap with the remainder. fdisk, mkswap, swapon are the main tools - some at least.
3) ~/.bash_profile and the like are sourced for login shells. ~/.bashrc is sourced when it's not a login shell. You get redundant path info but I usually just symlink them. If you have special knowledgeable use for them, they make a difference, though. But you do need *a* config file to use aliases and such like, or you just get stuck with the default /etc/profile setup.
4) Several ways but the easiest is to 'chmod 600 /etc/profile.d/bsd-games-login-fortune.sh' though that's global. (I like 'em myself - mostly.)
Man pages and just poking about the file system looking for cool stuff is good for brain-cramming.