Well my first and best advice would be to focus your deck as much as possible on one theme or win condition. The thing with Genex allies is that many of them were not designed to be used in conjunction with each other, but instead in other archetypes (they are allies to them, in this respect). Such cards include ones in your deck such as Bellflame and Reliever (meant for Neo Flamvell/ Counter fairies and Naturias respectively), that don't really have much of a place in the deck besides something that can be boosted by Genex Turbine to become a beatstick.
So my suggestion would be to take out all of the cards you believe are in there simply because they have the name Genex Ally or Genex in them. Bellflame and Reliever I believe are a good place to start. Also, the main theme of the Genex ally cards that work with each other is Attribute changing, so I would try to build the deck solely around that. I feel like the Controllers, Furnaces, and Gaia, don't really work in this situation.
Now I've never built a Genex deck before, but this really makes me want to try one. If I get one working I'll be sure to let you know. What I am going to try to build is a Dark based deck that takes advantage of Crusher and Duradark. If you can prevent your opponents from doing evil things like attacking you or destroying monsters, then you have a nice little engine that can destroy a whole bunch of your opponent's cards to give you some free attacks.
It may not be the best idea, and I may try something different in a moment, but like I said the goal is to start with a certain win condition in mind: "What way am I going to win by using Genex Allys?" Instead of "let's build a deck that has Genex Allys." Once that is out of the way, look at all your cards that support that idea, whether they are genex or not. If you want to go the changing attribute road, look at your cards that either change attributes or harass a particular attribute. If you want to go the supporting route, look at another theme some of the Allys can work in, like Birdman for Mist Valley or the Fire ones for Flamevell/Pyro.
P.S: just like there are certain spells or traps you put in most any deck, the same goes with monsters. Cards like Plaguespreader Zombie and Gale the Black Whirlwind, among many others, can help you get out of a lot of situations that your core cards may be unable to deal with.
When you've been around as long as I have, you know that the only worthwhile things you can bring to a catfight are popcorn and a drink. -Max Mercury
Genex Ally Bellflame Genex Ally Reliever Genex Furnance Genex Gaia Genex Turbine Machine Assembly Line Megamorph Scapegoat United We Stand
You seem to already have a slight theme of Attribute changing, and taking advantage of that with Duradark and Crusher. If that's the case, run 3 Duradark, 3 Crusher, and 3 Chemister. Since you're running so many machine Tuners, Genex Neutron, as Dekadense suggested, is a great card. Solidarity and Rivalry of Warlords also make for great type support, as well as giving some of your monsters better protection. Swords/Wall of Revealing Light also stop some of your weaker monsters, such as Changer and Crusher from being destroyed in battle. Dimensional Prison can also help protect your monsters from battle, aside from generally being a great card.