Hi again!

I'm putting my questions in seperate posts, to keep the threads focused. Hope that's ok.

I have been searching this forum already, but my specific questions where not answered.

The portal should be in three languages. German / English / Hungarian

Demand A
Users can choose if they want to see the forum in one of this three languages
OK, that's easy. I guess it's just about setting up different templates.

Demand B
Users can also choose if they want to see entries in all languages, one or two. The languages of an entry should be displayed by a small flag.
That's what I was thinkging: I'll make more fields like TITLE_EN, TITLE_HU, TITLE_DE etc. I'll also make select boxes when new sites are added which languages the homepage supports. So far so good. But how I make the templates display the entries that user wanted to see (one, two or more languages). Is this anyway possible as I'm thinking about it? What about the categories - is it also possible to give them names in every language?

I would like to use the dynamic mode. Is that ok? Are there any performance issues to consider or is just about the visibility for search engines?

Thanks for your help.