1) How does party size affect they way they interact with a map?
OD&D has doors being stuck by default, with a push required to open them. A roll of 1 or 2 opens, which gives you a stuck door 2/3s of the time.
2) If you play using this rule, do your parties get into situations where they can no longer explore a dungeon because of stuck doors?
Tavis Allison has a great post pointing out the detail filled maps of the Mines of Khunmar, including which direction doors swing open. Being the noob that I am, door swing direction completly escaped me. But now thinking on it, I imagine yanking open a stuck door or forcing one open would be equally surprise-ruining. Is knowing this detail about barring doors?
3) How has door direction come into play in your sessions?
*) After complaining about people making fun of playing D&D, I realized some people might be doing it to ease tension upon entering an unknown social situation. I mean, most people probably don't know what we do when we play and are afraid of "doing it wrong." (Although, the young woman I mentioned is probably not an example of this, she seems to look forward to Friday the way someone might look forward to cow-tipping).
And to make your time worthwhile, here is my coin for joesky (sort of like the OSR's boatman):
A rug weighing a stone and smelling of creosote, when unrolled, reveals a foot-high fire. When rolled up again, all heat and smoke dissipates, as if there were never a fire.