Breitest24 - Croom is one of the best trails for a good cardio workout anywhere. For sure. I'm thinking about it, and that's the only trail I miss right now from my office on the left coast.
It happens to everyone... getting lost. I got so incredibly lost the first time I went out there. I even got turned around in the last year or so there with the changes made from the "donation" of singletrack to the motorcycles.
All of your concerns will melt away in time. I'm not trying in imply anything about your fitness, but I think you'll find as you get stronger, the speed, water, and getting lost become a non-issue.