Hi,
1. If you are a developer or if you want to have the very latest code you can use svn trunk. I "try" to keep trunk stable but of course from time to time there will be bugs. The good news is if you report an important bug and are using svn then it will get fixed quickly and you can do svn update to get the fix right away.
2. Every time you do svn update, you should rebuild the solution and then visit /Setup/Default.aspx to run any db scripts and/or feature configuration updates. If there are db schema changes, then the version number will change, otherwise it will not. So yes, we may make code changes and it will still be 2.2.7.9, but most likely befor ethe next official release it will have schema changes and the version will increment. In any case the setup page handles it for you if there are schema changes.
3. The only way to package without the features is do a clean svn checkout and never build the mojoportal-complete.sln file, only build the mojoportal-core.sln and then you don't have to worry about filtering out any files because they won't be copied up to the Web folder. As soon as you once build the mojoportal-complete.sln, all the feature files get copied up to Web and there isn't an easy way to leave them out of the package.
4. Its especially bad if production is a root web site and your dev machine is like http://localhost/mojoportal. You will end up with broken links and images. The only way to completely avoid problems is if you can use host names in your hosts file so that your dev machine uses the exact same url as production. ie if the production site will be www.foo.com, then you need to make your dev machine be www.foo.com using your hosts file when entering content (and don't use a sub folder like www.foo.com/mojo unless it will be the same on production). So yes it can be done but requires trickery and its best to avoid it if possible. Only solution after the fact is to fix any broken links or images.
Hope it helps,
Joe