i am a morning runner.
I trained for both marathons NOT eating before my run(sometimes up to 12 MILES on an empty stomach!) I now realize thats just stupid and serves no purpose whatsoever. I make myself a banana/protein/ice/splenda smoothie that has approx 150 cals in it that i drink before i run or workout every morning. It has made a HUGE dif in my energy levels, and productivity of my runs, just fyi! I know we are all eating in a deficit, but if you can spare a few cals in the morning, youll feel a lot better, PLUS you use them up RIGHT away anyway, so they really could be whatever gives you the most energy.....PIXIE STICKS for all it matters
Regarding water-- i run with a handheld water bottle, so its not an issue.... BUT i do know if i forget to brush my teeth before my early am run, then i will have the WORST cotton mouth my entire run!
As far as adding more days...you will be fine if you add a fourth. But i think you might benefit equally well from trying to add a little distance (if youhave a distance goal~~ like 5 k or 10k..... if you want to start trying to add distance once or twice a week into your normal run schedule, than youll prob need the extra days off from running...you can always cross-train in between!