Good luck. You seem to be on to something with just cutting the old hose in ease of getting the fittings out. The fittings are the important parts since you won't be needing that rotten old hose anymore. I am not familiar with how your hose is routed, but it sounds like a pain. I wonder if there is an alternative to how you route the new hose, as in.... don't put it back in the same place but rather choose a different and easier approach to the path on the new routing. I know Mercedes has their intricate ways of doing things for engineering purposes but I can't see how routing the high pressure hose would affect anything differently as long as there are no severe bends that would stress the hose or output fittings on the pump.
I have'nt taken a sls pump apart yet....maybe someone that has done so can weigh in on if the pump output fitting can be clocked differently so the output fitting of the pump pointed in a different direction?.....like an alternator.