I have this same ski - and love it. And I also have a 2021 GTI SE. I will answer what I can, and you may need a shop manual or parts diagram to answer the rest.
The center console lid comes off by locating the cut out half circle where the lid tabs slide back and forth. The cut out area is where you can pull or pry the lid tab out of the channel it slides in without breaking the lid tab off. The cut out is so you only have to pull or pry a little and lift the one side up thru the cut out area.
Rivets have to be drilled out and cannot be replaced with screws. There are no threads in the hull, just holes, and no space to put a nut on a bolt, so that is where a rivet goes back in. I think I have used a 3/16 drill bit to remove the 4 rivets that hold the storage bin down. I have bought the unique replacement rivets at the Seadoo dealer and a rivet gun from Oreillys.
That all said, I don’t think it is how you go about tightening your steering bolts. I haven’t read the manual, but you should. I use Seadoomanuals.net for my ski. It has been a long time, so I don’t remember exactly, but I removed the yellow handle bar cover, and the plastic cladding around the steering, and had pretty good access to the steering bolts that hold on the handlebar. I had my console box out recently to access the fuel tank straps, and don’t remember seeing steering access bolts. Whatever you are trying to tighten, double check yourself in the shop manual first.