My understanding is that the base pay is unimpressive, but dealers make most of their money in tips. Given that it is pretty normal to get tipped nearly every single hand, that can add up. If a dealer is particularly friendly and fun, the tips tend to be bigger, especially at the tables where the players want to have a fun time. Also, in time, you will get to know the regulars, and if they like you, they will tip more.
As to improving your game, it ought to. You should be able to improve your reading skills in general. Not only are you not in the hand (and therefore not focussed on cards), you have the best seat from which to look at people. If you have also read widely about physical tells
, you will have a base from which to evaluate how pervasive certain tells are.
You should also be able to learn to get a sense of the type of table it is relatively quickly. This is also a skill when you want to play live poker. You want to be able to pick a table that gives you, with your style of play, the best chance.