Oh, also I finished a full reading of the 4e PHB. I don't recall ever reading it all back when I actually played 4e
I did skip the powers lists and the magic item lists - I was more interested in re-familiarizing myself with the rules. I can see the places where 5e14 streamlined some things for the better - the 5e Advantage/Disadvantage rules and Proficiency (instead of half level, ugh) are two standouts. But there's a lot I do like and I would definitely run this. That said, I'd try to find the underground character tool that I've heard is rumored to exist out there to support my players
I think I'm going to make a Quick Start guide for 4e. Making a QS guide is always for myself, it helps me to really understand a system. When I say Quick Start Guide, I mean a player-facing summary of the important rules, stripped down into as few pages as possible, with references to the area of the rules if the player wants to read further. Lots of bullet points