my first thought when it comes to removable parts are the interchangeable hands for anime figures and Gundam model kits (which are VERY DIY, but it's like Warhammer, cut numbered parts out and put it together and have moving parts/joints. Saying this in case you're not familiar with how Gundam models are put together/work), where you can pop a hand off, and put a new one in its place (like a ball joint, although I'm not sure how effective that would be if you use resin) or for interchangeable-weaponry and things, again I'd probably say to take a look at a Gundam model, they tend to just have holes that you can slot the weapons into.

In terms of dynamic anime style, I'd also probably point you towards Gundam as the box covers for the models can by quite dynamic and can be quite posable (I haven't watched any of it though, can't get along with mecha anime, but I love the robot designs). For posing and ideas, probably some more actiony anime (my first thought is Attack on Titan, but I haven't seen it in years and even then I couldn't get along with the show...). Black Rock Shooter I think as well had some interesting character designs and fight scenes, I quite liked teh style of that one. I liked the anime The Seven Deadly Sins (only seen season 1, I know season 2 is out, but I'm waiting for that to be complete so I don't have to wait for new episodes)... Maybe Digimon Adventure Tri too? I'm not quite so sure about dynamic for that one, but again, the fight scenes in taht can be quite actiony and it has a very different style to the original Digimon Adventure anime... One Piece is all pirates and things, I don't know if it'd be dynamic (another anime I can't get along with, so haven't really watched) but they definitely have some... unique character designs and character proportions which are probably worth a look.

actually, maybe not quite 'dynamic' but there's an anime movie called 'The Boy and the Beast', I don't know if you've seen it, but most of the characters in there are animal-based and theres a few fight scenes and things. In terms of designs (for various animals) I'm not quite sure if you'll find much in terms of different proportions for characters, but there might still be something to work with.

This is all I can come up with. I hope it helps! :3