Syncing can take a long time especially on low end systems and with lots of mods and paints etc loaded, also when joining a busy server. The mouse pointer locking up for that amount of time and then freeing up sounds normal. When I load into an MP server there does seem to be a point at which my HDD stops working, maybe this is when your fans slow down, but if I leave it for what seems to be too long, it does load. Had some issues myself the other day getting stuck and crashing when syncing with 14c and d after updating on Steam, but now I've removed and re-installed the game it's working again.
At least now it seems your ports are open for game play.
Looks great. I'm sure that most, like me, would like to see a vid of that in action
So for bike steering do you rotate the bars?
Also if you use an MX throttle you can easily mod it to be able to adjust the throttle rotation, currently I just have a bit of wood in there as a stop for it but you could use a bolt to make it adjustable if needed.
If your problem is local the most likely cause is a firewall or router. Check if you have any forwarding rules in your router relating to that port but sounds like you've not been in there before. You have reset your router too right?
Now I've got the view back to normal I really like this release. The grip levels seem to be more realistic, rear braking seems much improved and the rendering optimisations are noticeable and very welcome.
Noticed an odd vibration or horizontal view oscillation at slow-med speed when using the view not locked to the bike that I don't see when it's on (only tested in VR).