1. Share price has nothing to do with bankruptcy. Bankruptcy happens when a company can't meet its obligations and debts. If a company is profitable, then by definition, it met its obligations and debts so it cannot go into bankruptcy. You go to bankruptcy protection to ward off creditors. If you are profitable, you paid off your creditors and made money on top of that so there is nothing to protect you from.
2. Shorting involves borrowing shares. There are a finite number of shares that you can borrow. So you could have an infinite supply of money but your broker only allows X amount of shares available to short.
Shorting doesn't cause bankruptcy. It's a method of profiting when companies veer towards bankruptcy of their own accord.
Think of it as surfing. The surfer doesn't cause the wave, he just rides the wave.