Grabs can be broken on reaction but its definitely not easy, you can based on the arm that extends from the opponent judge if its a 1 or 2 grab. Some characters have special grabs with different inputs that can be broken differently, and can make it more of a guess but really landing grabs is more effort than its worth sometimes unless you play a character like King which can do some insane grab damage. I generally just guess input but im not fast enough to even react to getting grabbed yet, but it doesnt really bother me much because its possible to play around grabs anyways.
Tekken definitely has 50/50 stuff, but really it comes down to being able to judge what the opponent is thinking. If you are low hp he will almost always do a low to finish the deal, but they are extremely punishable so if you know its coming and block it you basically got your comeback served.
In the end 50/50's are there, but to win you want to be confident in your punishes. Its so satisfying when you notice patterns and can anticipate or punish stuff on reaction.
I couldnt recommend any Tekken game more than this one. Just pick up Akuma and youll be playing a better game with almost the same gameplay LUL Poongko found a 100% combo with him recently
https://clips.twitch.tv/EnthusiasticNimbleFinchPeteZaroll Or just any other character that looks cool, it seems like people are putting out a lot of info on almost everything so it'll be easier to learn since the game is kind of lacking on that part.