If you're looking for auto-detection and then page redirection for any specific version of Flash, I prefer the Macromedia kit which you can download at:
http://www.macromedia.com/software/f...eployment_kit/
Easy to install and get running. Unzip, edit a few parameters in the index.html and off you go...
As for usage of Flash for nav/graphic areas, as long as they have the plug-in, you're safe using it anywhere, assuming the ActionScript complies with the version you detect. For basic pre-animated buttons, text/bitmap effects, you can probably get away with a Flash 3 export. If you want to be able to easily configure the navs to accept parameters, new URLs, counters, whatever, you can require Flash 6 as the plugin and use a local XML file that contains all your navigation criteria.
If you have any more issues/questions about Flash, feel free to post here.
