Synergy and Concistency, well basic cards are missing in my opinion
-> Tour Guide
-> Chaos Sorcerer
Just because is a Chaos build... Tour Guide is mostly likely going to be usefull, chaos sorcerer has a ridiculous summoning condition for a chaos deck, 2300 atk and can banish a monster, I mean it's not destoy, it's BANISH, simply badass xD
Effect Veiler is a also a good card for chaos, simply because it is good in almost any deck, and is light and also a tuner that you can even use to make something like... catastor or gaia, with cyber dragon and level eater then normal summon veiler, etc etc, many options, it simply don't only negate your opps effect, but eventually can increase your synchro range.
I guess some Lylas would be good? since you don't run any mst, and it can mill, if by some reason you don't wanna mill in CHAOS deck you can still use Breaker... or just the MST lol, really I feel like what hurt most a chaos decks is the backrow.
If you're running two cyber dragons just put a chimeratech on the extra, because you run many repeated monsters on the extra and then why not, you never know when you will find some use for this, Zenmaines is a machine type so it have many uses.
I feel like if you could use rank 4 with this deck easyly... but you only have utopia, so far I found that if you only have 2 spots for xyz rank 4, I'd put Maestroke and Black Corn, because they just have a higher overall use.
I don't see so many options to summon dark and light dragon other than cyber dragon and level eater, it also MUST negate everything on both sides, so I don't really know how this will work.
Making the deck thinner would ofc increase the concistency, if 40 cards deck, duality and avarice still leave the deck without concistency, you should then also try upstart goblin, or maybe removing some monsters that don't really need to be there, btw, to get some concistency you should try Card Trooper, good because it mills, it reachs 1900 atk, and it still give you a draw when him dies.