Well, I dont see much advantage in introducing a HP system. SW is designed not as DnD. Each piece of the rules is stongly intereconnected. If you take out something it should be with good reason and substituted with a well thought out rule.
With a HP system probably combat becomes much slower. Everybody has to track HPs and the GM cannot throw anymore dozens of enemies or allies against each other. Our typical SW combats are ca. 20+ combatants. Our biggest SW combat was 125 combatants. We were able to finish this unforgettable and formidable combat in only 3.5h or so. (roleplaying included)
I doubt that this would be possible with a new HP rule where you have to keep track of so many creatures life energy. Even smaller combat with only a few dozen combatants would be slowed to a crawl, IMO. One of the strong SW advantages (large full-action skirmishes in comparable short time) would be gone.
But one thing this whole thread shows. There IS a demand out there for a game system which is as simple, direct, complete and effective like SW but also a little bit more deterministic and "tamer" than SW.