Looks great! Congrats on your first build and hope it does well in Edinburgh.

I think it's been covered pretty well already, but I've also seen both fuses as links and velcro covers. The key thing for the link is that it has to be safely accessed and removed by hand, so you're fine on both counts. Just make sure the people running the event know where it is and how to get at it.

One thing I would say about the link... that cable tie doesn't look very secure! If it gets hit by something relatively minor the whole thing may come loose inside, which might then rattle the fuse loose. I guess that might also be a tech issue, since if losing the cable tie would allow the link and holder to fall inside the machine, it could then not be removed, i.e., it would no longer be a functional removable link. So might be an idea to either cover up the cable tie with a plate on the outside, or better have the fuse holder secured inside with something a bit more robust.

I think coming in only-just-overweight is a great achievement. You've obviously planned everything out carefully! I'd say the reason you're on the limit here is you've started with a high mass drive system, 4 motors and big chunky wheels. There's not much left once you've built a box around that.