Question 1: Yes.
Question 2: Yes.
Question 3: Yes, because Squadrons are attacked as a single unit, with the actual element struck determined randomly (like TW-scale BA).
Question 4: Yes.
Question 5: SCR# refers to the number of screens an Element may launch in a single turn, and may launch each screen at a different hex. No errata needed, this is just a clarification.
ERRATA:
P. 352, PNT rules, at the end of the rules paragraph:
If using the Squadrons rules (see p. 326), PNT protects the squadron as a whole. Note the total PNT values of all Elements in a squadron, and adjust this total during the game to account for losses.