I use my 4WD occasionally. You don't use it on hard ground, it winds up the transmission (there's no centre diff). But there are a few times you really use it:
1. You have a lot of weight on the front end loader, and you were too lazy to ballast properly, so your rear wheels are light. With 4WD you can still drive, with 2WD you find one rear coming off or getting light, and then it just spins
2. A bit of mud or loose - even when the ground is just a bit wet you can easily lose traction
3. Uneven ground. A 2WD tractor is usually actually a 1WD tractor - they have an open diff. One wheel off the ground = no drive. I often have one wheel off the ground over and around bumps. Many machines will have a diff lock lever (usually under your left or right heel) that you step on (don't do this whilst the wheel is spinning, you have to stop first). But that age of machine may not.
4. Braking. Tractors usually only have rear brakes. In order to get any braking from the front wheels, you need the front wheels linked to the rear - i.e. with 4WD you're also braking the front wheels
When I mow the roadside at our place, which is also on a hill, I go into M or L 4WD, it gives me more control. Otherwise, if I'm on a bit of angle into the ditch, and downhill, on a damp day, I run the risk that I get one rear wheel off and now I have no control at all - no drive, no braking. 4WD is much more confidence inspiring. The downhill side of the road goes straight down, so I'd rather not lose control near that - probably wouldn't kill me, but it'd hurt and it'd break the tractor.
Is it essential? No. People have had 2WD gear driven tractors for decades. Still 100x better than a shovel and wheelbarrow. But given the price difference isn't much, what would I buy? An HST 4WD every time. A small tractor needs all the help it can get with traction.
Dad bought a mini-ex for his ditches and track work. Having a bucket with tilt makes a huge difference to put an angle on the track or ditch. A FEL can do a fair bit of ditch work, but for serious work you'd want a mini-ex. The question is whether you have anything in between that a backhoe would help with. Don't get me wrong - I'd love a backhoe. I think it would be awesome to just go out to the shed, put the backhoe on and dig some stuff. But the reality is that I dig holes of that sort maybe twice a year, and one of them wouldn't be suitable for a backhoe for some reason. And I'd have to store the backhoe the rest of the time, plus they aren't cheap.
Even with the mini-ex, I had Dad's old one at the house here before he sold it for nearly a year. I always used to ask him why he had a shovel out when he had an excavator, and he'd tell me reasons why it wasn't suitable. When I had it here at the house I understood. Every time you drive it on your lawn it makes a mess. It digs ditches wider than you need. If you're being careful, you really need to use a spade and take the sod off first, and you don't want to mix the topsoil into the clay. If you're just hammering through 200' of ditch a day every day, they're the right machine. But if you only do it occasionally and you want things looking nice when you're done, sometimes doing it by hand is better. I actually got a chain digger when I trenched in our irrigation system - way faster than a mini ex. I also cut my stormwater, my power, my sewerage, my garden water, all of which weren't where I thought they were (new to us house, but apparently all those services had moved around/been extended over time, so they didn't go in any logical places). I spend quite a bit of time fixing what I wrecked, and it maybe would have been faster in total to do it by hand.
It all comes down to money, time and fun. If you could find an L3010HST with backhoe on it (like that one above) for around $10K, that'd be awesome. But if you find a machine without a backhoe, I'd say you'll have almost as much fun, and do almost as much work.
If it were me, I'd buy without a backhoe (easier to find). Then if you decide you want a backhoe, I'd wait for a machine with one already on it (you already have a tractor, so no hurry), then sell your machine and buy that new one. Maybe have both for a while. Tractors don't lose value, you'll sell yours for what you originally paid, and a tractor with a backhoe already on it will be far more cost effective than trying to add a backhoe to an existing machine. Most of the guys on here have been through a few tractors, and it's not expensive to change them. Fun even. Better still, if you needed a backhoe you might find that you also need a slightly larger machine at the same time, or maybe it needs to be a bit newer, or have a cab, or whatever. The family financial controller is sometimes more understanding when you sneak up on these things.
EDIT: on trees, a grapple or forks at a minimum if you're moving tree trimmings. A grapple is best. You need a 3rd function valve for that, and again they cost a bit to add (circa $1K plus a grapple is around $2-3K). A tractor with a grapple already usually doesn't cost that much more - so buying a machine already set up with what you want would be more cost effective. But unlikely to find grapple and 3rd function in that age machine I think. I don't have a grapple and use forks, and they are far easier to work with than a bucket for branches, small logs etc. The bucket sides kind of tip everything out - they work well for soil/gravel etc, but not for trees.
