It’s good that you asked that, because I just checked and we don’t have the Razor Fang available in 3.1. We’ll make sure to add that in the next beta, probably somewhere in the Baykal Rainforest and also as a reward in the Casino.
You can get halfway to Gliscor by capturing a Gliggler in Rochfale Tunnel and evolving it into Gligar at level 22. After that, just equip the Razor Fang and level it up at night as normal!
I don’t think so… there are enough trainers in the game that it’s not hard to keep with the level curve, even if you don’t take extra time to grind.
The phone on the PokePod will allow you to call up trainers when you want to rematch, although it doesn’t work quite yet.