Mock-biting can be sexy and affectionate if it's not painful, though I've had one partner who simply could not control themselves and there was nothing sexy about it. Teeth marks are not a hickey.
Tickling is affectionate for about 2 seconds, after which it becomes annoying and very quickly after that, cruelty. I don't see how it could possibly be sexy, it's far too intense a sensation and distracts completely from everything else. I would consider tickling a total sexual mood-killer, because my involuntary response to tickling is to elbow the attacker in the ribs.