I LOVE Hoyt/Jessica. I was re-watching the episode today (WHY are they skipping episodes next week when they shown recaps constantly?!) and was practically dying at how cute they are together. As long as I ignore the fact that Hoyt is 10 years older than her.
I'm glad that I like the two of them so much because Sookie/Bill annoys/bores the hell out of me. I don't find their melodrama and Bill's overbearing concern or Sookie's childishness at all endearing.
As for Eric's tracksuits... I don't know.
I think, like someone else said, it's meant to ironic/disarming. The man likes to be comfortable, and what's more cozy than sweats and flip-flops? He only does the stereotypical black leather vampire thing for Fantasia.