From what i've seen he'd probably own in the EPL, may not offer much creatively right now but with a creative midfield partner and industirous wingers/forwards he'd control the middle pretty well i'd think.
Not really, it was a different competition, the only real similarity is that it was a continental cup. So winning them are the same thing technically in that each crowned the best in europe but you can't really compare the competitions.
This situation probably would never have happened if he went with Rafinha to celta and worked under Lucho in the first place, he would have been ready to break into the first team like Rafinha is now and if he wasn't we'd know for sure and we could just sell him off.
Its not like Bartra get outpaced everyday, and getting outpaced by Bale isn't that big of a deal. But I rather him stick to CB only RB/ RCB in 3-man if absolutely needed.