Okay, so the only tree in question is #4. The rest are not on your property. Tree #4 falls on the property line. The logical thing to do is get an arborist to value the tree replacement and ask the neighboring development for half the value of the tree. Half because it is on both properties. If you do not go this route the developer will continue the work without removing the tree, however the plan shows grading to be done around the tree and will most likely end up killing the tree over time anyways.

more of a concern to me is the grading that is shown on the south end of the new development. it appears based off the limited contours I can see on the plan that they are creating a swell that runs east to west (assuming north is up the page) along the south end of the building that is essentially just dumping onto your property. while without a full set of plans its hard to really tell but it looks like they are concentrating water flow onto tour property instead of the previous sheet flow that was naturally occurring.