Rehabilitation is more important than punishment, is that a good summation of the point here? Even a neutral tag would be overkill in your opinion?
I usually don't tag accounts for PM begging, but I do report them. That sometimes leads to a temporary ban.
My 2 Satoshis: I've tagged 2 Merit beggers:
Unsollicited PM asking to buy my account or 800 Merit.
Trying to buy (and resell) Merit.
PM merit begging.
I am willing to remove this once you have earned 12 Merit. Note that I don't mean just mean receiving 12 Merit, the merited posts have to deserve the Merit too (and I'll be the judge of that). Once you qualify, PM me and refer to this trust rating.
Both have more tags by now.