Actually it's a couple of questions... When installing php scripts do they have to be placed in the cgi-bin? Is it safe to place more than one script in a directory? Thanks!
No! Depends of script type and num of files! For example Joomla and SMF will be in different folders because this scripts are real complex web applications and u will need two folders for them! U can put for example script called random.php (returns random image from your site) and complexsearch.php (returns result from all search engines) in the same directory because those scripts have only few lines of code doesn’t include other files etc.
These days you can run PHP scripts from pretty much any folder. It is probably not a good idea. As a lot of scripts will use the same file names for example index.php. So you'll end up overwriting lots of files if you're not careful. You'd be better off having each in their own platform if they're more than just a few files.