yes you can borrow someone else's stock and sell it on...

yes you can borrow someone else's stock and sell it on market....that's why the hedge funds have the stock mkt by the short and curlies... The lender receives a fee for lending out his stock, but it can back fire if the price goes against him and he's forced to sell because of margin calls. It gets real interesting when the seller cant settle because the borrower says he would rather pay a fine than give the stock back. Then the broker is in trouble....Enter Tricom and most lately Bear Stearns.

Re the other stuff you mentioned, fundamentals are out of the window right now so there's no point doing your head in thinking about them...Que sera sera...