Gee, I don't pay attention for a couple days and everyone else has all the fun. But I'll add my 10c.
1. Definitely an MX.
2. I'd say your property is a bit big for a BX. It will do it fine, but you have enough distance that the 2 speed box will annoy you (slow), and you have enough undulations and woods that the ground clearance will annoy you. A B2601 is not much more money and only a tiny fraction bigger, but quite a lot more capable. An old table I made here:
https://www.orangetractortalks.com/forums/threads/bx-vs-b01-vs-b50.36719/ Note that the B-50 is now the LX, but basically same machine with same measurements. Note that the B2601 lifts twice as much on the 3ph, and about 30% more on the FEL, plus having quite a bit more ground clearance. The BX is built to a size - so far as I can tell it's built so that guys can sneak it past their significant other by claiming it's a ride on mower. It's a good machine, but it's compromised by its height.
3. A B or an LX would both work. Both have mid PTO and can have a MMM. The Grand-L can have a mid-PTO, but (at least in the USA) there's no MMM for it. And whilst a Grand-L is a magnificent machine, it's also expensive, and I don't get the impression you have limitless money. I'd say B is your minimum, LX is your "I just want a bit bigger machine".
4. Backhoe I personally could take or leave. I've lived without one and it hasn't upset me. I'm about to inherit a mini-ex, and I suspect that will be super useful. On our new property I might have been tempted to get one if I wasn't getting the mini-ex.. The great thing about a B or LX is that you can add the backhoe later (on the BX you really have to order at time of buying). That's what I told myself when I bought the B, and I never added it.
5. At your size of property, arguably you don't need a tractor at all. So you're really into "what makes me happy" territory. It's important to go and sit on them, they're much different person than you think. And they shrink when you get them home, so don't be scared of something that feels a bit big in the dealership. And if your budget can stretch to it, I'll mention again that a Grand-L is a magnificent machine, and if you had one you couldn't help but be happy.
6. Lots of people recommend rear mowers. I have a MMM and like it a lot. It's easier to manoeuvre and I find it easier for my better half to drive (and she mows the lawns sometimes). Lots of people claim they're hard to take on and off, but I take mine off all the time, it's about 1 minute off, 2 minutes on. The B is way way easier to take the mower deck off and on than the BX. Of all the implements, I think a BH is actually hardest to take on and off (the FEL is pretty easy like the mower). I think a rear mower works best if you want to be able to back it under low trees. A MMM best if you want to cut close to obstacles because you can easily see exactly where the deck is without twisting your neck. I mow a lot of roadsides and rough country with my B and a MMM, and it's pretty bulletproof. A flail is good buying if you want something sort of halfway between a rotary cutter and a finish mower, and that doesn't stick out as far as a rotary cutter. My feel is you're more in lawnmower territory than mowing fields......so I'd go MMM.