NN, 80%er and a 2hr run back-to-back is good going.
Keir, lol. I do use sticky notes for little reminders. I write things down like target paces, "No sticky buns" and "drink"!!! Hope the lurgy doesn't wipe you out. If your not 100% stick to short and easy.
Stewart, what BD200 said. Relaxation is the key - but it's not always easy given the stress of normal life. You will get the odd "bad" run where the HR is elevated, there will be a reason for it: stress, lack of sleep, dehydrated being the main ones. The HR is a good way of knowing whther you are coming down with something too. Your resting HR tends to be up ~ 10 beats.
BD2000, Seems a reasonable plan. I don't like to plan too far ahead, you may want to change things dependant on how you feel. But an increase of 1 mile per 80% run is very sensible. I would also plan to extend it to 70mins, and then when you get near to your HM , I'll give you a cracking session to do 1.5 weeks out.
I use the foam roller at home and do a few lower abs (knees to chest). Lots of stretching for lower back, hips and hamstrings. But I like to go to the gym as well, and use the swiss ball, kettle bells for dead lifts, dumbbells for lunges and the TRX straps for single leg squats and hamstring curls. I also do full burpees and jumping lunges. Planks, side planks, plank punches, pressup to planks etc. I'm not sure I'd still be running if I hadn't started doing the flexibility, core and S&C stuff.