I'm putting my votes in for the mystery trade, new shops, and the horses. I'd like the mystery trade if you get something good out of it. The new shops would be nice if they could be fit into the storyline and not cost gems to purchase. Horses would great as long as they're not for gems. I know S8 is a company that has to make money to keep going but not everyone can afford gems all the time.
Some new crops would be a nice added addition or even some new trades or another way to get trade tickets.