You mean detect thoughts? I would probably slightly prefer it as an SLA either at will or 3/day, but I suppose I wouldn't object to the continuous version.
Done with special abilities?
I guess CR 2.
Hmm, it's more intelligent than a spider, though an alien intelligence. I'd be more inclined to go with standard treasure.
It's got an alien intelligence (and Int 12). Who am I to tell it what to use the treasure for? But seriously, since it's an Aberration, I just don't see any particular reason to tie the treasure value to what a vermin gets. And it's certainly smart enough to use magic items and presumably coins if it felt like trading. I'd think it should have the ability at least to understand some language(s) also.
What about no coins, standard goods, standard items? We can note in the flavor that the items often don't seem to have any comprehensible purpose.
How about giving them the ability to understand Terran (even if you don't want them to speak it)? Umber hulks speak that (the similarity being average-ish Int underground aberrations).