I think it is a very individusl thing, hence the apparent lack of answers here. Try training 4 times per week, if it is too much, cut down to 3, if you are still full of beans, try 5, or even 6, but be prepared to cur down to 3 quality sessions if that's all your body can deal with.......you could always cross train on the othe rdays.
Went down from a stability/ control for severe pronators shoe to a "guidance" shoe for mild pronators, plus a lot of foam rolling, and a few stretches ( too lazy), plus keeping running, fixed it. Stopping runnning was totally counter productive, but I had to modify what I did to keep within limits of symptoms- which is how I discovered that run/ walk was the answer ( whilst wearing a knee strap for about 2 years).
Do you have a good physio you can go to? - Sounds like some thing needs "fixed"- shoe choice/ specific excercises needed, or something, rather then just trying to struggle on.
As a Dr, I would say avoid the GP unless they are specifially tranied as a sports doc, with an interest in running. Other wise you'll just get negative responses like "if it hurts when you run, stop runinng!".
There is bound to be an explanation for your hip trouble, and I think you need to get to the bottom of it, rathe tthan ty to push on through.
A DNF alway stinks, but try to make it a positive, as the thing tht fianllly triggered you to sort out whatever this problem is.
It isn't bad for a mass event- the main diffiulty is getting to/ from the race - public transort is the way to go. There are water/ lucozade at the drinkss stations, the usual goody bag, various stands available at the end if you need to suddenly eat a burger/ have a massage after you;ve run, OK , the T shirt is a bit crap, but reasonably well roganised- I ve done it about 5 or 6 times, but it doesn't fit with ither races now, and I've not bothered the last few years.
The course start in the middle of toen, and is sufficiently crowded that you'll struggle to get up to speed at thestart- later on it is fine.