I agree, visual customization has a lot of value, people like to differentiate themselves from each other or sometimes just get bored of looking at the same thing all day every day. In fact we agree SO much that we have plans to add this feature in the future.
Please tell us this is NOT the main feature next patch... There is so much more people would want to see rather than a visual customization feature. I'm not saying it's a bad feature but it is not that important IMO in comparison to other things.
Just a few things right off the top of my head that are easily more important than a visual custom option...
1. New Legendaries
2. New dungeons and or a new DEEP dark dungeon. Maybe it can have 99 lvls and every 10 levels it gets darker till the final one is pretty much pitch black with a guaranteed legendary drop at the end.
3. New shrines, bring back monster shrines, gem shrines (they can drop higher lvl gems that don't normally drop), explosion shrines, etc...
4. Mob density option (needed for acts 1,2) since act 3 is the way to go for XP.
5, Do something about Act 4 to make it more appealing to go to.
ETC.... there's A LOT more I can write up but those are just some quick ones off the top of my head that are more important.