LOL. Funny how I just brought this build out into the open yesterday and I see this up here.
There are some thing you need to take out and put in to make sure the deck is decently under your control without clogging the back row.
Take out Dark Hole, Malefic Worlds, Mirror Force and Crystal Raigekis.
Dark Hole, although destroying your own monsters doesn't seem to look bad at first, trust me, it is still bad, you have no attackers, and many a time I found this to be quite a dead draw late game as I don't have any slots on my back row to put my destroyed gem beasts to, but that's personal preference, if you feel you can use it to it's potential, go ahead and use it, it's your choice.
As for Malefic World, you already have an indestructible field spell Rainbow Ruins, and all you need is just ONE or more Crystal Beast in your back row. Meaning your Malefic Rainbow Dragon would stay there quite long. Not to mention Rainbow Ruins other effects such as halving your damage once per turn, spell/trap negation, a free +1 every turn and swarming another monster out. Definitely one of, if not the best field spell cards made.
Taking out traps is just to ensure you don't clog your back row and render yourself useless to using spells. The only trap that's good is trap stun, because it can be activated anytime you wish and does not have a requirement to be activated, making it usable as and when you like.
Add in 2 Rare Values, they give good draw power, and your Crystals can be retrieved with Blessing. Adding in 2 MSTs can't hurt you, since they clear your enemies back row early game, you don't want a D.Prison on your Pegasus, and it's too early to negate it with your field spell.
For Monsters, have 2 of each Crystal Beast, EXCEPT Mammoth and Pegasus. Reason? When you swarm with Carbuncles effect, you want to direct all tramplers/piercers towards Mammoth, lightening the damage taken, plus if you're going to abundance, Mammoth has 100 more raw attack points as compared to Tiger. And having 2 of each ensures you that even if any other Crystal Beast get's RFPed, you'll have one more JUST IN CASE, and the searching and thinning options of the deck doesn't make it harder to get them out.
Also, take out Malefic Parallel Gear, they're not part of the "swarming" potential the Crystal Beasts have, BUT you may want to put in just one, so as to take advantage of the swarming potential and having a synchro here and there.
Throw in 1 or 2 Dragon Queen of Tragic Endings, they're extra draw power, as if the deck doesn't have enough, and can be summoned pretty easily, especially if you only managed to abundance with 3 Pegasus, it could add extra attack, having 2600 DEF doesn't make it that bad as a wall either. Plus having it's own revival effect which I find somewhat helpful in clearing/controlling your Crystals. Hamon could also work as well, 4000 ATK and DEF. Beatstick AND wall of the year? I think so.
Apart from that, the deck should work out just fine, as there's no way your field spell can be destroyed, only replaced, and having a 4000 ATK beatstick isn't much to laugh about, just make sure to negate any Enemy Controllers or Book of Moons, as Rainbow Dragon has 0 DEF and even a treeborn frog could take it out in Defense Mode.
Whew. Mini-essay. xD All the best for your deck!