Suse has a system management tool called yast2 that might help you out some. You can add/remove rpm software, and should be able to reinstall postgresql.
Different linux distributions can install files in wierd places. I don't remember suse's defaults, but one way to find out is issueing a command to look for postgresql's text-based management interface:
find /* -name psql
Someone with more linux knowledge than me might be able to tell you if you can install an rpm to a specific location? As Dirk said, check the irc channel, they are helpful.
