Concerning that Infinity Stones = Gems idea...
Remember that in the comics the Infinity Gems were Pieces of God (well, a god at any rate). There's actually a seventh Infinity Gem out there that contains said god's mind called the Ego Gem (no relation to the living planet). So the Infinity Gems being alive isn't too far-fetched.
Heck, if you really want to make a crossover, you could have the Infinity Gems be the result of an incredibly powerful Gem shattering itself. That would fit with the comics too, since the Infinity Gems came into existence when said god committed suicide.
Yep. It was introduced in a crossover with Malibu's Ultraforce.
edited 19th May '18 12:04:01 AM by M84
Disgusted, but not surprisedThis is reminding me
of this old fan art thing from when Age of Ultron came out.
Ok so I just watched the latest few episodes (hadn't watched any since jungle moon) and
(deep breath)
WHAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAT
THAT THEORY WAS RELEGATED TO RONALDO TIER Y E A R S AGO
(also I'm gonna make a new account soon but I wanted to post this now)
edited 19th May '18 12:20:33 AM by SmartGirl333
Ronaldo Tier?
I mean, I can think of some theories that were Ronaldo Tier. The one theory that the Crystal Gems didn't care about Steven and that he was meant as a bio weapon. The one theory that Peridot was disabled and that's why she had robot limbs (this was before the limb enhancers were confirmed, by the way, people had just kinda guessed by that point). The one theory about how Jasper was a forced fusion and that's why she hates herself (god damn was that a stupid theory). But Rose being Pink Diamond wasn't Ronaldo Tier exactly. Close to it by that point, maybe, but not exactly.
Have you any dreams you'd like to sell?I mean the way the theory was made back in the ye old fandom days (and god do I feel old saying that), it was that she literally didn't have hands and feet because her Gem didn't make any or something. Or that her Gem possessed technology or something and the Peridot body she was in wasn't her real body or something.
Old fandom theories are weird. Makes me nostalgic for the heyday of Steven Universe and Gravity Falls.
Have you any dreams you'd like to sell?You know, I kind of wish we had Word of God telling us exactly how strong each of the Gems are, physically. Like, how much can Garnet bench-press, could Steven beat Pearl in an arm-wrestling match, and exactly how weak is Peridot? Is Peridot weak by Gem standards but still stronger than any human, or could Connie beat her in a test of strength?
Going back to the Infinity Stones as actual Gems, I found this nice art
in the Steven Universe tag.

It's kind of naive to assume that's not what that Word of God meant. This is at end of the day still a kid's show, and they're not going to go into detail about that.
And them being a different species isn't really an obstacle. They're not really that different to begin with, and gems are a species that are basically changelings and can shapeshift whatever they need.