You've already mentioned the two most popular ways to trim the edge of your field tiles. Another less popular, and more expensive way to handle this is to send some of your field tiles to a fabrication shop (or do it yourself with a 200-300 bucks worth of equipment) to have an edge on each tile bullnosed. It has a nice clean modern look to it. It is generally done on porcelain and stone tiles. But fairly less often on ceramic due to the requirement of having to also paint the newly formed edge with glazing. That same glazing step isn't necessarily required on porcelain...and never required on stone.
About the distance you should locate the tiles from the corner: Tile is installed level and plumb. The closer the tile is to the corner, the easier it is to identify a wall that happens to be un-plumb. So, if your corners are deal level, feel free to go as close to them as you like. Otherwise, hide the fact that your corners are un-level by holding the tile back from them a bit. The further they are from the corner, the harder it is to see the problem.