1) Already implemented. Hold shift and right click.
2) I've been trying to get this feature for literally over a year. All I ever get is shit from other devs and everyone telling me to switch to Tiled because they've never actually used it for large-scale games, don't know how incompatible with C2 it is, and don't account for all the layout editor features that would be sacrificed. That, or suggesting I import .tmx files into the Tilemap object which is a poor temporary workaround at best. What's funny is it's just an extension of the feature in your first request. Seems like it wouldn't be very difficult to add at this point.