For the "length" items can I put "minimum" to allow me to use barrels of varying lengths and different stocks?

Ex. Barell - 8.5" (min.)
OAL - 26" (min.)

Or do I have to just leave it as a number?

In the additional description, can I use this are to list all the other calibers I plan to use (that have already been engraved on the receiver)? Can I also put barrel lengths here as well (this is only if I can't put "min" for length)?

Ex. Secondary Calibers -5.56, 6.8, .300, .458
Alternate Lengths - 10.5", 11.5", 14.5", 16"

I'm finalizing the forms to bring to the CLEO tommorow and just want to make sure I have everything in order.

In case you can't tell, this is my first NFA form 1... haha.