Third party modules and theming - Questions

Hello there,

I am using Drupal since some years now, but today, believe it or not, I discovered "commons" for the first time. As it seems to be the perfect setup for a new projekt of mine, I installed it on a test environment today. Now I am having a few questions, and let me say, that I am realy sorry, if this has been asked before. If there're docs around for it, please refer me to them!

First - After I did install commons (alpha 2) I checked for module updates, and there're a lot of them. What I want to know is - Should I install all of em, or is it better to stay with those versions commons did come with? I am asking, as I am not sure if it might cause problems if I update them!

Second - What about the core? Installed version is 7.16, but 7.17 is the newest. It's the same questions as with the modules - Will it cause any trouble if I update the core?

Third - Are there any limitations regarding other mods (from the module database)? Or am I able to install all of them, despite that I might need to theme them.

Fourth - What about the core forum and advanced forum? Can I install it? Again, I know, that I may have to theme and edit the files, but that's not a problem for me. Just need to know, if it, again, will cause any trouble.

Fifth (and last) - Can I theme commons like drupal normal version? Template suggestions, views override, and so on?

Again - Sorry if this has been asked before. I tried to find answers, but it isn't that easy. :|

Thanks you very, very much for your help!