Will this tractor also serve as your primary lawn mower near the house, or just your larger open areas? 3pt finish mowers can make a nice cut, and cut large open areas quickly. However, for better maneuverability and time savings, you might want to consider opting for a mid pto belly mower. That will also limit your tractor choices because not all will have the option. Also, if you're mowing and making tight turns around sensitive areas, you might want to find the lightest tractor with turf tires. But keep in mind, while a lighter tractor will be better for mowing, a heavier tractor is better for utility and loader work.
If you can afford and justify it, forget the tractor as a mower and pickup a Zero Turn. Depending on how much grass you're mowing each week, you can get away with a smaller deck. If I was only cutting 2-3 acres, I think a 52" ZTR would be fine. You can probably pick up a quality new 52" for around $5k. Granted, it's more cost up front than the RFM (rear finish) but it will cut better, faster, less fuel use, and more comfort. And it won't tear up your lawn because of the weight. I much prefer hopping on my ZTR than my tractor.
Otherwise, all the tractor brands will do all the things you mentioned (besides maybe the mid pto)... Some will be slightly more capable in different areas, but each will shine in its own way. It'll come down to how you feel about each one when you sit on it, and how much you feel like spending.
For the work you describe, it doesn't sound like you'll need high HP for anything in particular. You can most likely get by with 40 or less.
I'll put in a vote for the LS R3039 (same as New Holland Boomer 35). 39 HP, fully loaded with deluxe options, good loader that lifts almost 2000lbs ... 3 range hydro goes for around $20k with a 5yr warranty. There are lots of great tractors in this size range tho ... that one would just be at the top of MY list for the best value when you consider the price and features.
But good luck! Tractor shopping is fun! Seriously tho, you need to sit on them all and get a feel. Then when you narrow it down a bit, read the forums here and look for what kinds of problems others are having with the ones you're looking at so you'll know what to expect for quality and/or maintenance after you buy it.