Speed of Types and Backups

I have two unrelated questions, and I figured I'd be lazy and ask here 
instead of running tests myself. :)  If there is a FAQ that explains this, 
I'd appreciate a pointer to it.

First question: Which types are faster for access: int or char, varchar() 
or text?  Should I specify a particular type of indexing, or will Postgres 
detect the best method?

Second question: If I *don't* use the -F option to cut down on fsync's, is 
it safe to backup the database live, or should I still just backup a 
pgdumpall?  Is there a better way to do it?