The Eres'al is an ancient spirit and possibly a goddess of the Eres (as well as the Nerek from
Midnight Tides, and probably some others). She was awoken to the world once more when Mayen blessed the Nerek in
Midnight Tides.
I don't think she worships Bottle, so much as she sees him as a potential companion. Bottle is very nature-friendly, and we can see this reflected in the way he uses magic. It's a lot more spiritual and natural than anything Quick Ben would generally use, and it's a lot more altruistic than what the Wickan warlocks use. As a result, she sees in him someone who she can communicate with. I'm not sure if you've read all of
The Bonehunters, since you made a topic about just finishing
Midnight Tides, so spoilers just in case:
Not Scabandari's child - it's just said that it's an heir to the Throne of Shadow, quite possibly the only possible heir. Remember, though; you can't believe everything you read in these books - the moment someone is absolutely sure of something, it's often wise to step back and question it.
Trull was raped because she needed Edur seed. There are quite a few theories concerning this, but I'd suggest you continue reading.