Why do you want Suárez to celebrate?
I think the 'don't celebrate against your old club' thing is silly. He's a passionate player. If he scores a great goal, in a Semi-final, it's a big moment in his career. If he wants to run around and towards his teammates / supporters and pistolero it up, good. He should. He's not rubbing it in Liverpool's face. He was probably one of the most talented players to ever lace them up for Liverpool, and while bonkers, he helped drag a pretty rubbish Liverpool side to further than it had before. He's done right by Liverpool, even if he did kind of make a stink to go.
I just think that if it's a big moment, he should be happy. He's not insulting Liverpool by being happy to score a big goal that he probably will remember for the rest of his life.
I mean, even Coutinho, if he scores a worldie, should celebrate it. I don't blame booing him, because how he did leave was a touch different, but honestly, Liverpool are in a much different state than they were before he left. His leaving made it possible to go out and get some of the talent they've gotten. If it's his dream move, fine. Rather have had him stay till the end of the season, but they got where they got with him or without him.
The players career is too short and could be over too soon to really hold much resentment or anger over someone celebrating scoring against someone. It's a magical moment to score a goal, and to do it in the Semis of the CL should be something they tell their kid's kids about. I would hate for them to have to consciously then turn around and hold up the hand and say, no, no, I won't celebrate it when they should be enjoying it. I mean, you don't have to stick it to the old club (unless they did you wrong, and neither of them should have that feeling) but there's a middle ground.