If they never show a sympathetic Anakin then how are you to buy into his turn in the final chapter?
You don't need to show him as a little kid to do that. Just because he's a hardass doesn't mean he can't be a good person. Just have it where his force powers bring out the worst in him, but to be kind and sympathetic in other aspects of his life. For instance if someone screws him over or he's dealing with a horrible person, I don't see anything wrong with force choking someone like that. What should happen is have Obi Wan to warn him never to do it again, and he does it a few times throughout the series to get information or threaten people he perceives as the enemy or getting in his way, until finally he goes to far and chokes Padme to death. He has to be tempted by the Dark Side really, and he should unconsciously admire the Dark Side. If done properly, Anakin shouldn't realize he's turned into a member of the Sith until he wakes up in his suit with 3rd degree burns.