An interesting concept.
I don't know how Slyness is supposed to work. The reaction bit to Hide. I mean, if he's standing in the middle of a white room and gets smacked by a sword, how is he hiding? I think you're giving out too much at 2nd level, anyway, so I'd drop that bit.
A minor housekeeping thing: I find most featu4es that give a number of uses based on an ability score modifier say something like "you can use this abilitu a number of times equal to you Int modifier (minimum of 1 use)" instead of "1+int mod times." I think you ought to change Obscure Arcana to work that way.
And I'd simplify Tongue Tie to just have all the effects on a failed save without bothering about the fail by 5 or more.