Will be going to NH next weekend for the first time.

1) How is security up there? Is it safe to make a tent, leave tent/sleeping stuff inside and hike to the top lightweight?

2) Are lean-ins semi-private or are they shared among large groups? DO people reserve lean-ins before camp site? I'd prefer not to drag tent along if I don't have to.

3) Do people hike to the top with their full gear or is it better to leave stuff in the car (or tent, as asked in question #1)), hike and come back at night to grab sleeping gear?

Thanks