[ Hey, he's just trying to help a bro out here. To be honest, that last bit is entirely because he's not sure how Buffy would handle a de-souled Angel these days. There's years between them, after all. ]
Th' thing about gypsy curses... they're a lot more complicated than you'd think. In Angel's case it was designed to torment him for all eternity. Make him pay for his misdeeds. The most vicious and ruthless vampire to ever walk th' earth, suddenly forced to deal with every ounce of guilt and remorse that got stored up in th' absence of a soul? I'm sure you get th' picture.
That wasn't all though. If he managed to experience just one moment of real happiness... poof. No more soul. [ Pause to let that sink in... and here comes the punchline. ] He did that once. With Buffy.