For me it's the best way to avoid any further problems and i go through most of them whenever I want to play on any casino.The reason is sometimes they also update the rules about which we need to be familiar with and it's best to read them from time to time also to check for any updates.It doesn't take much time and can save you from withdrawal problems also that can occur later on in case of violation of rules.
If you read the rules before you start to gamble, then you should be fine, if there is a chance after you register and after you start to gamble, it should be the responsibility of the casino to let you know that there are some changes in the rules, they should notify you that rules have changed. If they change it, and notify you (a pop up would be enough) then you should read it, if they do not show any indication that the rules have changed since you last gambled, and in the middle of it, then it would be their problem.
This is why there is always a good case against the casino who changes their rules later on, and why they make a rock solid one at the start.
There is no plea of not familiar with the rules and if you violate any of them you can't withdraw your funds as they have full right to stop your withdrawal and freeze your account.That is why it's advised that you must check the rules of casino first of all to have smooth gameplay afterwards.But yes casino also must be legit on which you are gambling.