If someone has 5% share and 5% short selling at the same time,...

If someone has 5% share and 5% short selling at the same time, that means that someone has zero share in the company. But, that someone can still have 5% votes in the company, that is weird and government stop this sort of practice if it's happening. It's not fair at all.

If I have or can borrow lots of money and I buy decent amount of shares of a company, then if I shortsell all of the shares indirectly, I still be a share holder on the register and the company has high number in short selling. So, even with practically zero sharing I could control some or all of the company.

DYOR, I am no sure this sort of practice is even possible. If it's possible, short selling numbers mean nothing and it won't be reduced forever, 'cause it does not need to be paid back.