I've had an
L6060 HST since 2015. I just traded it for the cabbed
L6060 HSTC version this fall. I use the tractor pretty much the way you propose with most operating hours devoted to mowing & plowing. For those operations in the heat of summer and the cold of winter, the heated & air conditioned cab has been a godsend for me. The only downsides to the cab are reduced visibility when working with pallet forks at full height and attaching SSQA implements. I now use a camera system to fix this issue. The cab is also a problem when working in the woods. For those operations, I use the open station MX5800 instead.
1. The LA1055 lift capacity is considerably more than the LA723 on my old
L3430 but not quite what I'd like. FWIW, the published specs on the LA723 were way overstated. However, I found the published specs on the LA1055 to be fairly accurate. Check the hydraulic pressure and make sure it's at or near 2800#. I know some who boost it 10% or so to get more lift but that can take it's toll on the front axle.
2. No help here.
3. The DPF has been almost a non issue in the 700 hours I have on the
L6060's. The Intellipanel gives you a readout on the status. Keep the RPM's up and work the tractor normally during the regen cycle and you won't have any trouble.
4. I had the dealer install a T&T kit on my first
L6060 and it was a disaster. Clearance problems and leakage made the kit almost unusable. A T&T is definitely worth the money but as others have said, get one from Fit Rite Hydraulics! No problems at all since I went that route.
5. I've had 7 Kubota tractors in the last 35 years and I've found the R4 tires to be a good compromise between traction and lawn damage. Don't mow in FWD if you can avoid it. Turf's are the best on grass but require chains for working in mud & snow. I'm also curious about the R14's but can't offer any opinion at this point.
If you have, or plan to get hydraulic SSQA FEL attachments, a 3rd function valve is a must.
Even if you don't need them now, get all 3 rear remotes. The cost is far less than adding them later. Yes, the Kubota valves do bleed down a bit but IMO, it's only a minor issue. I haven't had any external leakage problems like others have reported.
If you get a cab, the 170 amp alternator, defrosters, and rear wiper are all well worth the price. Get the front & rear cab lights mainly for the wiring & switches. Throw away the halogen lights and replace them with LED's. Skip the Kubota radio and get a plug & play aftermarket model with more features for about 1/4 the cost of the factory model.
Good luck!