Well, I do think that backpacks / bags should be used more in general. As for general use, I do think having many items in your inventory is just messy and lacking overview, so most people tend to use a bag/backpack for that. backpacks in general are what one should see most adventurer being using. Those bags are used often as well, but I do think they are only for minor things (scribe writing stuff, coins, maybe a knife). As for restricting thief RP, I do think a thief will have no problem whether you're carring a bag or not. A skilled thief will probably steal food from your mouth and you won't notice it
(just joking, of course).
I do think we should see more use of pockets / bags / backpacks, but most people use them.
As for the OP's question, I do think 'check' is without contact but extremely evasive. It's like somebody's walking around you and looking you up and down extensively. The message 'Foo examines you intensely' suggests that in my eyes. You're being looked as if you could have hidden something (maybe think the stare airport security would give you looking if you have something to hide). Physical contact would mean it'd be extremely difficult while hidden, so I think that's unlikely.