My website is currently being stored by a web host (HostGator to be specific).
For the most part, for most of the web scripts I use (php, etc), I simply setup the database (with phpMyAdmin), FTP the script files to the appropriate directory, set chmod permissions, and maybe edit a few config files.
Is DimDim a good web meeting script for people like me that use a web host?
If not, will the installation process ever be close to the example I listed above?
No - you may need to upgrade to a virtual or dedicated private server.