re Amy's Wednesday run - it's not a problem with speeds the days after a long hard run or race.
I had a terrible session Tuesday and didn't feel great Wednesday but didn't matter as Sunday was ok which was more important and likewise Amy more important you ran well Sunday than Wednesday.
In theory each mile raced takes a day to fully recover - ie 5k three days, 10k six and half-marathon a fortnight and marathon a month (but potentially more) - training miles aren't the same as they aren't at the same intensity but if you are hitting targets reasonably well on Sunday, don't worry so much about being slower than the targets on Wednesday.
BRB - yes, it indicates you have more than sufficient speed and speed endurance to run a 3:50 marathon - as long as the endurance matches it and the pacing is right on the day and conditions are good.
re Iain's comment - either he doesn't think what i've written previously is of note or he might have accidentally blocked me on the forum (or deliberately?) - of course he can't read this so can someone else inform him he may have blocked me accidentally -it happened on the Tom sub-3 forum thanks