Hi...
a) COPA1_XXXX archive the below tables.
CE1XXXX
CE2XXXX
CE3XXXX
CE4XXXX
CE4XXXX_ACCT
CE4XXXX_FLAG
CEALE01
b) You are right.
c) Refer to Note 1836261 - CO_TOTL_AO: Archive totals records for reconciliation objects
Refer to Archiving CO-PA Transaction Data - Controlling (CO) - SAP Library