I'd advocate more Genex Ally Birdmans, rather than T.G. Ultra Chicken: Birdman's ability to turn himself into a beatstick while bouncing back your "When this card is Normal Summoned" effect monsters to reuse is far more powerful than the possibility of 500 effect damage.
Maybe more Spiritual Wind Art Miyabis rather than 2 of your Token Feastevals/Stampedes? Feasteval doesn't do anything much to advance your own position and bring you closer to winning, it's a card designed to use up your own cards in an attempt to prolong the game (and too often just to prolong your defeat). Stampede isn't as bad, but your tokens will still only have 1000 ATK (maybe 1500 if you have Rising Air Currents out) which doesn;t seem to me like enough to break through your opponen't defences most of the time - I'd rather be sacrificing those tokens to Miyabi in order to knock your opponent's cards out of the game for the forseeable future.
As for the extra deck, the easiest way to work out what to put in is to look at what level of monsters you have out on the field at most given times. How often do you have multiple Lv 3 / Lv 4 non-token monsters for Xyz summoning? How often do you find yourself in a position to Synchro Summon Lv 6 and 7s?
After a little thought (but bear in mind that I haven't actually played with this deck, unlike you, so my advice is not necessarily that well informed) I would recommend removing Dyson Sphere (I quite like the card in general, but my experience is that it doesn't do enough to justify the effort of bringing it out), removing Superdimensional Robotic Goon (will only work if you have 3 Lv 4 Planes and 2 tokens simultaneously, don't see that happening enough to justify including it) and maybe even remove 1 of your 3 Plane xyz monsters - 2 should be enough, I think. Consider Genex Ally Triforces (while Triforce doesn't do much on its own in this deck, it's a machine and thus works with Cyber Summon Blaster and Limiter Removal, asnd can then be turned into Big Eye or Gaia Dragoon)? Black Rose Dragon? Photon Streak Bounzer is also possible.
I'm assuming Dewloren is a mistake, and isn't actually meant to be in the extra deck, since you can't even summon it using this deck (no water monsters, after all).
If you did go with all the changes I've suggested, you'd have something like:
2 x Gaia Knight
Black Rose Dragon
2 x Genex Ally Triarm
Mist Wurm
Leviathan Dragon
Utopia
Gear Gigant X
2 x Phantom Beast Plane Xyz Thing
Photon Streak Bounzer
Big Eye
Gaia Dragoon
Gutav Max
Just my $0.02 (or £0.01, in real money

)