Let me first start with your Chaos Deck.
It is a formidable Deck being well balanced and very flexible. Not to mention with enough fire power to spare.
The High Level Selection is pretty good and see no reason to alter it. However the Low Level do need changing I can see.
I believe you have slumped your Deck with to many supports in terms of monsters some of which you do not need. Aside from stretching your offense. ((In this case to its limit)) They can be too slow a asset to be relied on with this type of Deck on a larger scale.
Magical Merchant: I would replace 1. 2 is pushing it.
Mask of Darkness: Needs to go. I will modify your Spell and Trap selection to decrease your Trap Count anyways.
Battle Chanted Locomotive: These cards has very limited potential at best. There are much better options for speeding your Decks capabilities.
Spirit Reaper: I would replace 1 as it is only a support. If you feel that you need to stall so much then its save to say there is something wrong with your Deck. These designs are best manufactured to deal a constant pressure to the opponents to limit there options steadily threw offensive measures, and thus decrease the odds for them to rebound against you.
Ok that leaves 5 monsters to work with and I now the perfect ones to consider, and yes looking at the Dark Monsters that are available.
Morphing Jar - This is a card I refuse you to pass up. The extent of its advantages can be devastating to the opponent if used correctly. In a regional you will see that the card advantage can play a big roll in determining the outcome against a powerful opponent.
D.D. Assailant - The double edge blade for the opponent. Perfect for helping reduce options in many ways if used consecutively in a Duel. I would add in at least 2.
Kycoo the Ghost Destroyer - A monster that if not used in the Main Deck should be Side Decked. In the new banned list you will still find threats such as the Sacred Phoenix and Zombies mainly. Still on the casual level this cards ability proves most useful.
Cyber Jar - Can be tricky with a opponent that knows what they are doing. However the advantages are great either way.
Archfiend Soldier/Gaint Orc/Vorse Raider/Exerion Universe((Japanese Staple for years, but has lost some work as of late)) - Just a maybe to keep up a decent Offence if room is left.
Now then that should seddle the monsters you have. To your Spell and Trap Cards which a lot of changes can be provided. After seeing your Trap Counts I can see this Deck has a real issue with its playing speed and option base. Sorry to say but this can easily allow the expert players with there aggressive and much faster Decks to simply overwhelm this Deck. Besides I must point out that since Royal Decree has become so much more common. You will find a popular use especially in the upper bracket of skilled Duelists on top of other threats such as Jinzo. Needless to say the use of so many Traps in this type of Deck is a outdated concept. It can prove a costly set back.
Smashing Ground: Great card but there are some better ones I want you to use. So lose 1 of them.
Wide Spread Ruin: Far beyond outdated card to use.
Time Seal: Nothing to really say
Trap Hole: Wont bother
Sakuratsu Armor: You don’t need 3 of them. Take it down to 1.
Ok that leaves 6 to exchange with, and mostly to the regards of Traps.
Here is the following cards I suggest looking into.
Scapegoats - This is a staple you MUST have!
Enemy Controller - The swiss army knife of the card world
Royal Decree - Staple support for a offensive design
Card Destruction - Can be a great support that at least should see use in the Side Deck.
Gaint Trunade - A Tech card respected by the professional. It can become most deadly once used with ether Snatch Steal or Premature Burial.
United we Stand - A power house card for a crippling blow if not a finisher.
Brain Control - Was used in the World Champs Deck afer all.
My Body as a Shield - A card you would be careful to consider. It may be costly but its uses are near endless combined with its quick-play advantage.
Well there you have it. These are all the changes I would incorporate. I hope they become helpful to you.