Q1-2 - Do you have a kiln manual or can you find one online? A "hold" is a temperature stay and is used for maturing a glaze during a glaze firing.
Q3 -An easy and cheap way to test if the kiln is ready to open without a pyrometer, is to roll up and stick a piece of paper in a peephole. If it catches fire, smokes or singes, don't open the kiln. Paper burns at 451 degrees.
Q4 - Nope
Q5 - Wiping it down will not matter. Be sure only to kiln wash the top of the shelf and not get any wash on the sides or bottom of the shelves. This is a lesson I learned the hard way!