Most of the advice is (imho) sound.
Just be aware that joining as a WSOp isn't what it once was either. You will effectively have no say in what type of WSOp you could become.
Back when there was a choice of WSOp trades, I was asked questions about AEOp's. The conversation went something like this.....
Them: "What can you tell us about the AEOp role?"
Me: "Nothing. I haven't got a clue!"
Them: "But you put it down as your third choice! Surely you know something about it?"
Me: "Sorry, I haven't got a third choice!"
Them: "Oh!" (re-reads paperwork) "You are correct, you don't have a third choice, do you!"
RUMBLED
I had looked into the role, which was how I knew it wasn't for me, but I am convinced that if I'd answered the question, I would have been an AEOp.
Luckily I stuck to my guns and got LM as I wanted.