I'd argue he definitely has the physical capability - strong and fast with a good engine. In terms of being disciplined, he's played right back for the majority of his career so I presume he knows how to play there. I'm not sure we've seen enough of him in attacking areas to completely right him off his technical ability, but defensively he's strong, good in the air and a good tackler.
Bacuna had a great game last night and deserves his place in the squad for now, and long may it continue. However, he has had very good games at full back before (home win against Chelsea a couple seaons ago for one) and then regressed in other games. I'd argue Micah is the best RB at the club and, longterm, I'd be happy for him to be our first choice.