In some cases, the distances given for the hikes on our website are just estimates. However, in the case of hikes in Harriman-Bear Mountain State Parks, all of the trails have been carefully measured with a measuring wheel. These detailed measurements appear in the guidebook Harriman Trails: A Guide and History, the new edition of which should be available within a week. So, the measurement of the length of this hike should be exactly correct.
I have found pedometers to be quite inaccurate, especially when hiking on rocky, steep trails. Remember, a pedometer measures distances by counting your footsteps, and it is normal to take a shorter step when negotiating rocky or steep terrain. So I am not entirely surprised that your pedometer would normally record a greater distance than that indicated by measuring the trails with a wheel.
You are indeed correct; it seems that, in the course of uploading the hike description to the web site, two paragraphs were omitted. I have fixed the hike description, and the missing paragraphs have been restored. Thank you so much for bringing this to our attention!
As to your second question, portions of the last part of the route follow footpaths where you must pay careful attention to the blazes. I would not recommend doing this part of the hike when it is nearly dark.