I am going to tackle a few things i personally as well as many others would probably agree on.
#1. After completing campaign on your 1st nee cycle character we should have the ability to fully skip campaign awarding passives and idols. The current partial skips are kind of a mess. With future story content coming it just makes making a new character a drag. Replayability is making new characters and trying new builds with items you farm on your main.
#2 CoF and merchants guild, currently if you do campaign on a 2nd char. Get all you idols, and passives you can then go straight to monoliths. However if you dont get to the final town you will not have the ability to visit cof or merchants guild.
#3 Monoliths on 2nd character. Once unlocking empowered monos on your main these should be account unlocked. Target farming takes time and we want to keep that nice progression up at a nice pace.
If any of these topics are taken into consideration it would hands down be #1 for me.