But this is a guy whom I could see breaking a rule to passively-aggressively make me break up with him. And I'm not having that shit.
He does not inspire trust in you for a romantic relationship. But you want to date him in a polyamorous context when you are mono anyway...
just so you are able to spend more time with him? To me, that is baffling.

Could it be emotionally and mentally safer for you to spend time with him just as a pal instead, and not as his romantic interest/dating partner?
It's like you want a lot of rules to help keep you safe with him in a romantic context, but you worry he's not going to honor your boundaries.
Maybe it is easier to just accept that while you are attracted to him, he's just not a safe person for you to be with as a romantic partner, because he does not inspire trust. You seem to want to be in a mono relationship, and he doesn't want to do that right now. He wants to experiment with polyamory.
So, how about just friend-zoning him, so you can enjoy his company more safely, and be free of all these worries and anxieties, since you are an emotionally sensitive person? You do not sound compatible to me, and you aren't even out of the starting gate.
I mean this kindly-- these things are not boundaries. They are stragegies to allow you to pretend you are in a mono relationship. You could take better care of yourself by choosing dating partners more carefully.
I most definitely don't want to know/hear anything about other girls he's seeing.
You don't want to see STD screens and know they use birth control and safer-sex practices? Ack.
I'm focused and intense and the thought of having feelings for two people at once would make my head explode.
You know this about yourself, but you are dating a man who wants polyamory, which means he could have another sweetie besides you. Well, you are signing up for a head explosion, then. Why do this?
When I'm with him, I want to feel like the only one he wants to be with. I want quality connection and I want to feel special. But here's a scenario I could see happening: what if he calls me by the wrong name? What if he gets our dates or preferences mixed up? That would ruin my little bubble and it would hurt my feelings.
So what are you doing for yourself to minimize getting hurt? You're choosing to date this man anyway, putting yourself at emotional risk that you do not want. Baffling.
You'd rather be in a "fantasy bubble" than deal with the reality that if you date a poly man you will be in a poly network with him.
What if his other GF gets run over by a bus and he is called to the ER? That gonna pop your bubble too? Why sign up for this emotional hoo-hah if you do not want to deal in this?
Again, this doesn't sound compatible. You don't seem willing to accept that yet. It's like you are trying to bargain with yourself to make it work.
You could: be friends
. There's nothing wrong with having a good friend. Or date someone who can offer you more than a "fantasy bubble" of the model you actually want; someone who can
actually give you the model you actually want; not a fantasy of it. Just
it.
There's nothing wrong with monoamory. There is something wrong with you putting yourself in the line of fire, running around creating all these "protections against getting hurt," when the simplest thing would be to date someone who is more aligned with what you seek.
Galagirl