Random thought: suppose rainbow ponies had a special caste, let's say Uberponies, that had all the "special" traits of the 3 breeds of pony? 4 wings, 2 angelic and 2 demonic, 8 legs, a poison bite, a horn, 2 tusks, bloodsucking, tentacle... Naturally, these would need to have like a 1 in 150 chance of appearing, but I think it would be cool.
I think combining all the traits of royalty would be a bit much, we'd end up with something that had two tentacles, two tusks, a horn and a grasping mouth. That's pretty broken even before we start considering giving it eight legs, web, wings and bloodsucking. A slightly less extreme option could be mixes of three, pick one from Earth/Keshi/Draltha, one from Pegasus/Darkbolt/Slippy and another from Unicorn/Tentacle/Gorlak. If people like the idea, it seems the sort of thing that should wait for after the diomedians get jazzed up.
Nice ideas for armour, Sorceror. Boots is a perfectly fine name, remember Rarity's line in Winter Wrap-Up: "And even though I love my boots, this fashion's getting old". If we just call them high boots, it'll be fine. Although, with the barding, if it covers two joints down, wouldn't it also cover the head? It's not "down" as in towards the ground, but down the list of dependencies, i.e. eyes need a head and the head needs and upper body, so barding would cover pretty much everything? Or have I derped again?
The spiked armour thing gives me an idea, I could add a muzzleduster and a spiked muzzleduster. The muzzleduster would be a hammer equivalent, and the spiked versions would be low penetration piercing weapons. Sure, multi-graspered ponies would wield them with their whatevers if you let them, but at least it makes sense, unlike a pony competently wielding a warhammer with their mouth.