On the topic of alts, also. I'm kind of torn. I used to be heavily in the 'oh god, why does this game let people play 3 or 5 or infinity characters?' But, when I was like that...I was actively playing 3+ games, with 1-2 characters on each, so it didn't matter to me. Currently, I have characters on a number of games. Reno, Eldritch, some star wars game, a couple others. But almost all of my playtime goes to Reno, and as soon as Hunter opens, I will have 3 characters there, and will be active on all of them.
Back to the XP thing briefly, I have a ghoul PC on Eldritch, who has 30xp currently, and has done 2 scenes, ever. (Literally.) Is that really hurting anybody? I guess you could make the argument of 'oh what if I suddenly start playing her, befriend Joe, and proceed to help PK poor Jane with all my idle-accrued RP', I think that is such an outlier, unlikely to happen situation that you shouldn't base your XP policies around things like that. How often do we seriously see PK these days?