7.3 has some video embedding options built in; ubbdev will have a strew of additional ones once 7.3 is out the door (in fact, once i receive worked that PubBeta is out I'll push some through).
You'll need to customize a video embedding option for clipshare though; I believe their latest version doesn't even use a flash embedder anymore and instead uses iframes (yuck).
Not sure what you mean about logging in to the same profile on your forums though... You'll need to make sure whatever option you use for your portal sets the ubb cookie if that's what you're attempting.
