If you went the opposite direction would it have you running at better areas geographically? Weird question I guess, and we don't want you running against traffic and putting yourself at risk or anything...
I started running without the C25k program. If you continue to increase your running v. walking you should continue to improve even if you aren't specific to the program. I can't see why tweaking it would hurt your progress, as long as you get the same amount in. Though you lose the cool voice prompts...
Good luck!