Exposed Beams

Hello, I know this has been asked a million times, and I have read a million articles on hanging drywall, but I cannot get the answer I am looking for. Everywhere I look it says to do top down because then the gap is left at the bottom and will be covered by floor trim. So then, using the same logic, wouldn't crown molding cover the gap at the top? Obviously it's less work to hang from the bottom up, and it's only me and my wife doing the work. So if anyone could explain to me why I should not be doing it this way, I would seriously appreciate it! Thanks in advance! Steve

We're remodeling our bathroom, but when we did the demolition job around the tub/shower area (removal of bathroom tiles and backer), we also tore off some of the plaster wall and backing adjacent to the tiled area. We've installed the cement board in the area to be tiled, but I was wondering what would be the best way to repair the non-tiled wall area? Is there a simple patching solution?