How would you assess Fuaga? Do you think he’ll be another future Willie Roaf or at least a future multi- time Pro Bowler

comparing a rookie LT to a HOFer is crazy lmao
Not really. I vividly remember watching Armstead for the first time back in 2013. All it took was 2 quarter, and I called my father and told him that we found our next Willie Roaf.
Concerning Fuaga, i'd move him back to RT if possible. I don't know what Peat is up to these days, but i'd bring him back and let him play LT and keep Penning for backup.