It has been suggested before in this thread that having your resolution set to high can cause crashes. Try lowering your resolution to around 1440 and see if that helps. Speaking for myself I have had no crashes and I have the games resolution set to the default resolution for the game.
I was experiencing the same thing. I actually started pressing F1 when it was loading instead of at the main menu or on the campaign map and it oddly started working with no crashes. Well, not any frequent crashes. I have no idea why this helped in my case, but I'd give it a shot.
For one turn construction... I select my town or city. Then active the one turn construction and select what you want to build. Then deselect it and reselect it. Hopefully, that makes sense.