I've been playing a "v2" Mystic for a while now; one problem is they don't give us enough time to really play-test it in real life.
At first glance, this looks great, but there are a couple of glaring problems that have not been fixed:
1) multi-classing is pure speculation - personally, my PC is multi-classed (with Mystic Theurge; I was originally considering multi-class with Wizard), and with my DM we agreed I could use Spell Points for a combined pool of Psi and Spells. It's not necessarily over-powered, but I'd guess it wont feel right for everyone.
2) the ability to change your Psionic Focus whenever you want is just way too much, and in v3 it looks even worse as the options are more numerous - for a bonus action, which not all PC's will have much need of, you can cherry-pick from all sort of cool stuff that no other class can get, let alone 'at will'. My own PC took Mind Vault and could abuse it to basically be proficient in whatever skill or tool the group needs, all the time, which is silly as it invalidates the point of being in a group where you need a variety of characters to form a rounded whole, not just one PC who can do anything and everything. In version 3, "Nomadic Mind" is an amended version of this power, and it's still got the same problem. At a minimum, you should only be able to change your psionic focus during a short rest - you can still be flexible, but need to plan ahead.