I really want to see hurdles like chaindrives disappear....because limiting peoples' ability to travel at speed makes this game a grind.....all about holding a button down. Maybe even two buttons, if you're travelling with a JD.
But I agree, there should be some sort of multiblock structure system. Perhaps we can get more complex power generators (Using fuel, I'd hope), various material-gathering, planet- or nebula-based structures, etc.
Perhaps somethings that require some a set list of components and require certain components to touch each other, allowing for the user to design a multiblock structure based on the basic blocks, but can be expanded....if you make it right.
Anyway, that was just an idea that popped into my head that allows for experimentation and customization, yet still retains some semblance of logic and removes accidental and/or unnecessarily unintuitive mechanics (Chaindrives, docked reactors).