1) I was surprised by this: " It will not pull a box blade or work the FEL without weighted tires." Is that on the flat?
2) Am I expecting too much from this tractor?
1) On flat ground a Backhoe is perfect counterbalance to Front End Loader lifts. On slopes, however, a (tall) Backhoe raises the center of gravity of the tractor decreasing tractor stability.
Bare tractor weight distribution is 40% front, 60% rear.
Add a Loader and weight distributions becomes 50% front, 50% rear. (+/-)
Pick up a bucket of DRY material and weight distribution becomes 60% front, 40% rear. Rear wheels should stay on the ground but rear will probably feel light.
Pick up a bucket of WET material or a green log and weight distribution becomes 70% front, 30% rear and there is a good possibility rear wheels will lift off the ground, putting all the stress on the thin front axle which is pierced so it can pivot to steer the tractor. Front wheels/axle may not be aligned perpendicular to tractor, consequently three wheels can be in the air in an instant, rolling the tractor.
"Loading" rear tires 50% to 75% full with liquid acts as ballast on compact tractors, however on subcompact tractors the rear tires are so small "loading" with liquid does not add much weight.
On flat ground a Backhoe is perfect counterbalance to Front End Loader lifts and should return weight distribution with bucket loaded with wet material to around 40% front, 60% rear.
Box Blades are often carried as FEL counterbalance. Box Blade should balance weight distribution with FEL bucket loaded with wet material to around 55% front, 45% rear. (Box Blades vary considerably in weight.) Caution advised transporting heavy FEL loads: KEEP THE BUCKET LOW.
The farther counterbalance weight protrudes to the rear the more effective counterbalance is due to leverage. Therefore 130 pounds of loaded rear tire weight on a subcompact tractor is LESS effective as counterbalance than 130 pounds carried on the Three Point Hitch. Regardless, Max25 rear tires should be "loaded" to lower tractor center of gravity working your sloped land.
The ability to pull a Box Blade relates to tractive power. In order to use a Box Blade the Backhoe must be removed and the Three Point Hitch components installed, then the Box Blade mounted on the Three Point Hitch.
The most important factor in tractive power is tractor weight. Other factors: wheel/tire size, 2-WD or 4-WD, air or liquid in rear tires, tire type, sharpness of tire tread, Loader or no Loader, tractor horsepower; in about serial order. Tractor tires grip some types of dirt better than other dirt.
Weight of Box Blade is important, as is weight of load being transported in the Box Blade. With just 21-horsepower at 6,000' altitude, I speculate Max 25 will not have enough engine power to spin the tires = lose traction. If it does lose traction you can lift the Box Blade a tad and allow some of the load to flow out. The soils in Tulare County are pretty tough. A light Box Blade behind a light tractor will consume considerable time making multiple passes when grading.
2) Mahindra Max 25 is a subcompact tractor, the lightest category of authentic tractor.
Subcompact tractors are mostly used in low stress residential landscaping applications.
Max has minimal ground clearance to cross rough ground and downed tree debris. Expect to "high-center" regularly working uneven land. Pushing with the Loader will usually free a high-centered, 4-WD tractor.
Max 25 with 25-horsepower at sea level will produce around 21-horsepower at 6,000' altitude.
I "guesstimate" FEL lift capacity at 700 pounds with ample counterbalance. About four wheelbarrow loads.