I feel you should be able to remove tree stumps for additional building space. Either as a separate tool in the toolbox or they should be removed with woodcutters as they chop down trees.
I understand that these places might want to be kept around in case you want to place a forester there to grow them again, but maybe then the stumps could be kept under the building you put on top of them? So if you realize you have made a mistake, you simply just move/remove the building on top of the stumps to gain access to them again?
Or maybe there could be an option where you can plop down a forested area and wait for it to grow. Not like the wheat field where it is a set square, maybe a bit more random in final shape?
Thanks,
Amy