Well I think I chose the wrong tool for this particular idea. C2 seemed to have everything I need in simple and quick-learned package. Yet physics is not one of them. I've just realized I can create instances on the fly, but there is apparently no way to refer them from the physics engine. Well, my bad. I should have tried free edition first.
I don't want to give up on C2 though. GM would take me a lot more time to get familiar with. That's why I ditched the idea of learning Unity in the first place. I have experience in coding in some languages but nothing suitable for games, plus it would take me ages to make something professional looking and fun to play. I like how you can make a lot with just several events, that would normally require tons of lines. As a game designer, graphic designer and programmer in one person, C2 is maybe one and only way to make game(s) in reasonable time and without spending months or years getting familiar with it.
I'll try to re-think the whole concept without physics, but it will most likely destroy the whole gameplay. I've seen some very complex games made with C2, so I guess if I avoid physics for the time being, there shouldn't be "anything" that I couldn't do with C2. My OT stops here.