Just googletranslated the writing (I only looked at the picture before) - I wouldn't worry too much about the animation. It will be possible - but it may be low priority at the moment compared to some of the other things which need doing.
The hardest animation work is what Karpov has already done, and what he is doing now - which is trying to match original animations (despite different frame rates etc).
Compared to this, adding extra animations to existing characters would be relatively easy, as the animations can be adjusted from what has already been created. I did a couple of test animations recently to see if it was possible - none of them are useful or worth looking at, but technically the process worked. As said, Karpov has done a lot of the most difficult work already. If you think of texturing, it can be much easier to adjust or recolour a texture once someone has created the original, compared to making an entirely new one yourself.
Regarding game implementation / skill stuff - it's probably not something we have to worry too much about at this stage - it may even be the case that the devs don't want this sort of weapon in 2238 - but other mods made from the same 3D resources will do. Regardless, I'd be pretty happy with it being under thrown or small gun (maybe crossbow under small gun, bow under thrown?). Crafting suggestion seems good to me also.
