How does it work in other games? Has anyone done a be-a-pro mode a few runthroughs before? The only one I've done was Madden (something).. but never got past the second year before giving up due to the typical unrealistic scores you get playing full length games.
I also do not believe that the start of the career will be grossly easier than once you reach the higher tiers. Yes, your opponents will be of a low skill set, but so will you. I also believe the nature of cricket in general will not always guarantee everyone becomes the best of all time, or make it possible to guarantee it every time, especially if the opportunities you get throughout the career are realisticly random (for example, fail on your first attempt in the test side, then not have an opening come up again for another 5+ years).
I also thought about the way to play earlier in your career, following on from the discussion of how skill points are earned and 'assigned'. I believe you'll benefit more from playing a range of shots throughout your first couple of years to at least give you a good level for all cricket shots before you start specialising, as to avoid having glaringly bad shots in your arsenal (for example, going through the first few years not playing backfoot blocks, then when the pace or spin against you really starts to ramp up, you have no skill in blocking late).