Thanks for that. Nice to see another running on board ;-) I'll follow you (but waaaaay back since you run quite fast)
Well done on completing a marathon. It's not a small thing to do.
The shorter races should work out well for you now that you have all that endurance, and the confidence to go long.
Did you run that distance before? It wold be interesting if you did to see how much your times improve now that you are a marathoner. ;-)
Endurance definitely helps my speed at shorter distances. Since training for my first marathon, where I dropped the pace & effort I ran my long runs, I've got personal bests at every distance from 1 Mile to Half Marathon.
I recommend to all runners I coach to pay more attention to the effort and pace of their long runs - nearly always they are going too fast.