Alright I'll answer.
Isaac - Yes - Needs to develop his mental though, give him game time and a mentor with the highest mental stats in your team (as long as the personalities match. Don't forget PPMs either. Individual focus: Strength.
Samba - Yes - Seems solid enough. I'd retrain to AMR too, Ind Focus: Quickness.
Dinheiro - Yes (probably) - Reason I say that, is I have never had a good time with Brazilians in the EPL minus maybe Neymar, Ganso and Felipe Anderson. I'd train him as a Poacher, but I'm sure some would disgree with that. Ind Focus: QUickness/Strength.
Andrea - No - I'd wait a year or so, get him some mentoring and hope his mental stats improve.
Romero - Yes - I'd retrain to AML, his only drawback is his teamwork, couple with his stats pointing to him being someone prone to running with the ball I think you'd need to teach him the PPM 'Looks to pass rather than score' and it should balance him out a bit. Ind Focus: Dribbling.
I don't have time to do the rest but you should see how I've picked up on certain things and you can apply that to the rest.
Don't always be fooled by the editor and those that look only at PA - You have to get them there, and I've had players that've maxed their 160-170 CA (Yes I have the editor) and gone on to do amazing things. Sime Vrsaljko is a great example, nothing with him is that special but he is a great FM12 player.
peACE