@Yxnder Nice detailed support request!
It appears your support request may have been overlooked. Can you provide an update?
There have been several Brave version updates (currently 1.36.112) and I am wondering if any of those resolved issues 1 & 3.
For issue 2, if you haven’t already discovered, you have to submit a wallet unlinking request following the instructions in this post: Unable to re-verify wallet - #118 by Mattches
Below is a Help Center topic that explains device limits/wallet linking. The device linking limit is going to be removed in a future version update. Hopefully soon! Lots of community members are eagerly waiting for this, myself included! 
How many Brave Rewards wallets can be linked to my crypto custodian account?