Crossword puzzle clue "it may come with answers"

It may come with answers

How many letters are in the longest answers in this puzzle - or how many of these answers there are

Letter appearing only in down answers; its opposite appears only in across answers

Letters dropped from six answers "come together" here

Retail come-ons ... and what the starts of the longest Across answers can be?

Really come down, as illustrated by hidden words in six starred answers

Summer blazer, which can come before the starts of this puzzle's four longest answers

"Come one, come ___!"