I'm not going to even pretend that I know what is best for a piece of land or whether digging up stumps or grinding them is better. I just want to answer the question about what to do with all the stumps once you dig them out.
My answer is; put them back in the hole. Just make sure to put them in upside down. I live in the Granite State. That means we have lots of rock and trees, but we're a little light on dirt. I've been clearing my land (10 acres) for about two years. I'm not clearing all of it. Just enough so I can have a nice yard for the kids (about 1 acre) and to have some trails that wind through the ten acres.
I had considered hauling all the stumps to a obscure back corner of the lot but figured out that unless I want the land to look like a battlefield, something would have to go in the hole. An excavator I know in the area said that one of the options is to flip the stump over in the hole. This way you don't have to pay expensive dumping fees, buy dirt, excuse me, soil
or have an eye sore.
I took an Environmental Science class and I think that burying the stump will provide nutrients to the land as it decomposes, though the process will take years. You do have to accept the fact that as it decomposes, you will have a sink hole again. This suits me fine because by then I'll have won the lottery and will be able to buy soil and even afford to have someone else spread it out.
Anyway that's what I'm doing unless I want to put a different tree in the place of the one I took out. I.e. take out a pine that can hit the house and replace it with fruit tree or magnolia etc.. I'm using those stumps for fill elsewhere. I don't think stumps make the best fill, but I have lots of erosion because of water run off and I need lots of fill.
I do like the idea of stump grinding which is probably what I'll do with some of the stumps, because pulling up a particular stump, might destroy the roots of the healthy non house threatening tree next to it that I want to keep and that decomposing stump should provide nutrients to the soil/roots of the remaining tree.
Ken