No, the 'bel' in the name is a template attractor. Loki, Katie, and Rapunzel all have original names with 'bel' in them that aren't the ones they've been using since relocation to their adoptive homes. Promise's real name has a 'bel' in it and she has no parents.
Juliet has reasonably high unpleasant company potential, but mostly not from a default state; you have to irk her first. Butterfly's sociability is wearing very thin under stress and I'm not sure yet to what extent it will grow back after pealing. Sierra's not going to be too terribly friendly, though she'll get along very well with a small handful of people. Cayra's slated to become somewhere between "embarrassment to her alts" and "totally socially insufferable" for weird magic reasons, though it's possible the alchemical trait blend threatening to cause this will turn out somewhat better than predicted. Golden is more serious than most Bells, and this makes her particularly tricky for some of the less serious characters to find common ground with, but I mostly think of her as being bad company only incidentally; she also has the largest cohort of in-the-know offscreen friends/family and feels less interest in forming close social bonds with people from farther away.
Shell Bell, Angela, Cam, Sarion, Glass, and maybe Aether if she's paying attention, make my first niceness threshold within the peal. Pruning that field depends on exactly what kind of niceness you're looking for. Ace and Cymbeline and Katie and Maurabel are likely nicest of the threaded unpealed. Insufficient data on unthreaded.