1. One character per account.
2. Limits to multiple crafting proficencies but not making it impossible to get them all. I am thinking siege perilous type skill gains where at a certain point you can only gain x per day or week so if you focus on one it will finish in a relatively acceptable amount of time, but multiples would only be for the people who love it.
3. An off line resource system (wow garrison / archeage farm) but no carebear poorly made socks, gotta toughen it up
4. Meaningful reason to play when you have a "bank" "maxed character" etc. focus on end game.