Let me start off by saying that I like the concept, because it opens up the door for awkward characters, and awkward characters are fun to roleplay in my opinion.
As for the progression, you've got the power points spread out, the speed boost spread out, and a -3 Con that takes place over the same time as +4 Str, +4 Dex, +3 App, +2 Int, +2 Wis, +4 Cha. I personally think that since you're using the Appearance score here, the Charisma shouldn't get boosted at all. You mentioned nothing about the infected's force of personality changing at all, and since you're already boosting their Appearance score, it doesn't seem like there's a valid reason for a Cha boost. (Taking it away would cut down the LA a great deal, a +4 boon to Cha is nothing to sneeze at)
The Lust weakness is great, and will come up a lot in the type of game that this template is most likely to appear in, that is, a BoEF/Nymphology game.
The flavor is good, the description is good, and the picture is good. It's very "you", Star. I'd say a +6 LA, personally.