Personal part collection on the web (Bricklink or alternative)
An alternative to using BrickLink for those purposes would be http://rebrickable.com. I personally find the interface to have some warts, but definitely better than BrickLink in a lot of ways. In particular to your requested features it does support importing parts from sets (Look for the "Add to my Parts (Part out set)" link on any set description page) as well as importing from Bricklink Orders in XML format and a few other sources. If your long term plans involve selling some of those parts on BrickLink it also supports a decent set of export options that can help out with that as well.