I'd very much like to see the ability to fuse parts together.  Maybe as an option along with pyro and invincible since it could be detrimental to the game's intentions and gameplay,   but I think if we could fuse pieces together to create singular solid objects it might make it easier to run the game for people with craptastic PC's like my own in addition to increased stability of the craft itself.

So,  you just activate the fusion mode in the menu and the fuse button will appear which will allow you to fuse two connected pieces (including braces).    I'm not sure exactly how this would work out or how much it would impact performance but it seems like it would help,  by limiting the number of free objects the game is trying to keep in order.