I can only answer some of your questions.
1. Salckware is one of the slowest distros to make new releases. They don't rush it.
2. Applications are upgraded by the application developers, not Slack. Slack releases application upgrades when the are made available. Or, you can get many from Slackbuilds.org
3. The latest stable Slack release is 13.1, I doubt you'll see support for such an old release as 4. Why not upgrade? it's free. http://www.slackware.com/
4. IRC = irc.freenode.net ##slackware
Have fun programming for Lego Mindstorms.