[alex.sk]

Ok, first of all:
DO NOT CHANGE URL STRUCTURE ON A LIVE BOARD
if you care about your Google rankings.
I didn't expect any questions in this direction, so I didn't even mention it in the first post.
Use a test board. Plan your moves and have redirects ready for your old urls if you decide to move.

Ok so what about us who are already using the vbulletin friendly url htaccess rewrite (minus vbseo)

Major link rot.
Same as installing vBSEO on a live board, atop of existing vB4 urls. It's a change in url structure.

Currently the board with this plugin activated will not recognize standard vB4 urls (forums/ID-name, thread/ID-name etc) and will not redirect them to resp. forum/thread-ID.html urls. I can be done, btw, I just didn't even think of it.

Also are there any changes to be made to the htaccess to achieve the urls above?

RewriteRules from the first post are necessary for FRIENDLY_URL_REWRITE mode to work.
Same as with standard vB4 urls.

final kaoss, which vB version do you use?
That looks really bad, but the only runtime-created function in the plugin is used in array_map(..., preg_split(...)), I wonder what could go wrong there.
In any case, I guess I'll try it one something more recent than my 4.0.3 in a day or two, some maybe there will be updates from my side.

what is the point of buying vbseo after vb4 ?!

None?
For me, it's about moving from vB3+vBSEO to vB4 while keeping the links intact.
An alternative to this plugin being vB4+vBSEO, which, I totally agree, makes little sense.