Terasec,
i didnt have a stool, and found the windows a bit high for sitting on the ground,
for kneeling the view was better but could only stay in that position for so long,
had enough room to draw,
The folding stool that Gametracker sells is excellent for use inside blinds like the Doghouse.
Those little black holes you mentioned are probably just small spots where the ShadowGuard blackening covering did not take to the nylon material. All of the blinds I have owned..Doghouse, Doghouse TSC, Penthouse and Hunters View Waterfowler Blind all have them but none actually leaked when it was raining.
Hope this helps.