eg. Yesterday I got wind of my company about to go bust so I sell. Today the shares are virtuallly worthless; the company folds. The broker / market maker can't sell them so does he just hold on to them and suffer the loss?
"What Happens To A Company Share When It Is Sold?" - Your question seems to be assuming that a broker buys the share and then tries to sell it. That's not what happens, there is no middleman, a share is only sold if a buyer buys it. It does not go to a broker at any stage they are only involved as an intermediary and take a %age of the deal as defined in their dealing contract with their customer.
When a company share is sold, its register of members (the shareholders or stockholders) is updated to show that the new shareholder now owns part of it. the transfer of ownership is recorded by the issuing institution,When you sell a company share or shares through our online share trading system, the process is quite different from that of a sale of best stocks to invest in.
//That's not what happens, there is no middleman, a share is only sold if a buyer buys it//
I don't think that's right. Without a "middleman" it would be impossible to accurately match specific quantities of shares sold to buyers. And who benefits from the bid/offer spread?