I have no idea why the spool shaft broke, I don't think you could intentionally break it even if you tried since it is internal. Plus I don't use my loader nearly as much as you. The dealership said they had never seen anything like it.
The 2501 has an extremely responsive loader, which is surprising considering the hydraulic flow is essentially the same as the B-series. The power steering has a lot more effort. As far as dragging a blade, I think it would do OK. So far, I've only done york raking with it. The horsepower is not the whole story. My B2920 had a 1.3L engine; the 2501 has a 1.7L engine with less power. However, my B2920 produced 58lb-ft of torque while the L2501 produces 70lb-ft, and all at a significantly lower RPM.
Other observations are the the L2501 still has a 100% mechanical, no engine electronics, drivetrain...but does have direct fuel injection. As such, it starts up tremendously well. In my opinion, it starts up 10x better than my B2920. I use zero glow plugs. In the cold weather it will still probably need them. I like the 10 gallon fuel tank. The b-Series does have more room for the operator though, and a smaller transmission hump, and a nice rubber floor mat, and someone nicer control levers.