First, I disagree that most of the playerbase is entitled. In fact, I don't think it's doing you any favours by using that word at all. It's been bandied about way too much since KotFE dropped, and it doesn't encourage a discussion.
However I do agree about there not being enough of an introduction to group content in-game. It's too easy to get partway through the game without understanding how to use interrupts etc. There should be some content that introduces players to their skills, and the trinity, for example. I also think it would be a good idea to have gear-check for the harder content too. That way newer players aren't subjected to abuse when they end up in group content, and experienced players won't have issues with multiple wipes.
I disagree about having to study guides though. I think the game should have enough info already in it so that players understand their class and gear etc, and tactics should be learnt by doing the content. If players want to improve, then the guides are there, of course. But by trying to make them a necessity, it becomes too much like a real-life job. No game should feel like that.
Perhaps there should be missions, similar to the intro. to group finder for each flashpoint. For example, intro to hard mode Hammer Station. That way, new players could all group up and attempt/learn the content, without it affecting more experienced players, and without having to take a test before playing.