Well, I didn't used to have that option, since sleeping with you only just started giving points, not that I have issues, because I do headpats everyday, and occasional spankings. That said, I like keeping the love/obedience over the slut score, and the morning alarm clock and other events can occasionally make that a challenge. I had to stop the morning alarms to give myself a buffer. (787/637)
As for the gifts, I thought the point was to make them more useful, and being able to give one to them on their birthday (once a year) is not the most useful thing in my mind, and it also means that Runey would have to pick an actual date, and track that, which could cause issues if there is a birthday event, like that one with Ashley. Seems like more trouble than it is worth.
As long as it is over a base amount, the love stat is mostly superfluous anyway, so it seemed like just a nice little role play thing, and I just can't think of too many other ways to use them that would affect anything. I mean, it's essentially a porn game, so I figure everything should lead back to sex at some point.... lol
Also, you have to keep in mind, that since this is a harem game, most of us won't just sleep with only one girl.