When you posted this thread you informed us that you do not have permission to parse all of these sites. So to answer your question, yes this is all possible, but without permission you should not be doing it. From your first post:

"grab all the data out of this forum - and get it local and then after wards put it in a local database - of a phpBB-forum - is this possible"?!"? "

You are essentially wanting to take user contributed data from various forums and copy all of it and insert it into your own forum. without being given permission from the site owners. IMHO big no no.

Martin