Morning, this will be quick as I have to drive to Devon in a mo.
Minni: Clearly you have no problem with endurance with 7 marathons under your belt. I'm sure we can get you below 3-30. It took me 23 marathons to break that barier myself but once I had done it once it became second nature which I think to a large extent shows that it was for me a mental barrier rather than a physical one.
I'm glad your using P & D schedules I happen to think they are the best out there for marathon runners,particuarly as they include a medium / long run mid week. Having said that I don't use schedules anymore as | work on the on the principle of one long run, one tempo run, one speedwork session, one medium long run and fill in the rest with swimming, cycling or running will get me there. If I'm serious about a marathon then I know I need a few weeks around the 60 MPW to get me a good time.
A few more questions to see where we are starting from, do you train with a club?, what are your 1/2M & 10K PB's?, do you regularly race? As you will soon realise I will race anything be it running, swimming, Triathlon, Aquathon, Duathlon, but this approach most definately isn't for everyone and probably doesn't give you the best results you could achieve with being more selective.
Anyway as I see it I'm not here to coach you but to give you the benefit of the years of experience, if you have any particular doubts , problems, questions, ideas etc fire away and I will do my best to help you out, if there is anything you don't want to put on the forum send me a PM.
Right got to go will try to look in tonight or tomorrow morning
DD