Hi 7acher and welcome to TBN!
I spent nearly a year and a half visiting Daves Tractor in No Cal before finally making a decision. My struggle was between the 2015hst and the 3215hst.
We have a 1 acre plot, mostly open with a few narrow spots and a cluster of oak trees.
Dave was kind enough to let me demo both of these units fitted with FEL & Backhoe. The 2710 BH on the 2015hst is no slouch. You will, however, have to be careful when digging because it has plenty enough oomph to upset the tractor.

It has the same specs as the 3710 BH which fits on the 2615, 2815 & 3215. (I think the only difference is the sub frame mount since the 2015 has a smaller frame). The 3215 felt more stable with the BH due to its heavier build.
The 3215 is suprisingly easy to maneuver and is only about 6 inches wider than the 2015 even with the 5' FEL.
I had my wife come with me and drive/operate both of these units. She had never driven a tractor before. It only took her about 1-2 minutes to get comfortable with either machine and she was moving the dirt pile around efficiently within about 10-15 minutes. The xx15 hst series tractors are very easy to operate and highly maneuverable.
You mentioned enough projects & work to keep you busy for quite some time. I have found for every 2 hours of planned work I have there is at least 1-2 hours more unplanned work that I find to do. I believe in the "if you want it done right..." adage. Sounds like you subscribe to that sentiment also.
I ended up getting the 2015 hst W/FEL, PHD & clamp on forks and will have a box blade shortly. I am still seriously considering the 2710 BH and expect it will make a great Christmas present.
The only reason I didn't get the 3215hst was the small size of my borderline residential property, the relatively short list of projects (which I know will get much bigger), and deciding not to start my own small tractor service (to get the tax write-off).
I would strongly suggest you AND your wife test drive BOTH the 2015hst and one of the slightly larger models (2815hst/3215hst) you may be suprised at how easily and precisely they all handle. There's nothing like actually sitting on the tractor to get a good feel for it's size. If you two are truly serious about the long term you may find the larger units to be more advantageous.
It sounds like the limiting factor is clearance between the trees. Be sure to take your own measurements (outside of tires and length from front edge of FEL to back end of the tractor). Don't forget how precisely you can maneuver with the hst.
Consider the lift height and capactiy of the 3215 if you are going to be wanting to move construction materials onto a roof or elevated platform.
Ditto on LAWALLSTRACTOR comments regarding the skid steer QA.
Good luck with your decision, You'll be happy whichever way you go!
-Ken-