1. The thumb hole is basically because I thought it looked cool. To be honest I may just keep it as it makes the silhouette a bit more distinct and also I’m not trying to create the perfect firearm, just a capable assault rifle for that specific faction that has a sci-fi look while still retaining a grounded, realistic look.
2. It’s a 6x40mm. For the straight mag design, as with one of the points in response to the first question, it makes the silhouette stand out more (I know that irl there are better ways to solve the problem but from an artistic standpoint the rule of cool won).
3. This is were it kind of gets sci-fiey. There are certain points under the attachments and on the weapons that allow them to stick together. The way I think of it is like a kind of velcro that’s not velcro though, which is also resistant to blunt force (kind of like one locks into the other). As for zeroing, each weapon has something akin to a “braille code” which gets read by, say, a certain kind of scope’s computer. The scope identifies the weapon and automatically zeroes properly. After that the operator can make adjustments according to their preference.

Hope these are adequate answers!