4. IF asked for source of funds by your bank/taxman, declare it is income from renting out the storage room
That's defrauding the tax man.
There's legitimate tax avoidance. That isn't it. You're lying about the source of your funds.
The tax man has seen it all and nailed it all. I expect anything relating to the UAE will be looked at extremely closely.
You may well be fine. I wouldn't bother myself for the sake of a quiet life.