Regarding the nature of the debit card transactions...
It's always best to check with the bank of course, but I've seen slightly different descriptions of valid transactions (those counting towards RCA requirements), including purchase and debit, even for the same RCA. And I'm pretty sure some other RCAs I've had use the term "POS."
Interestingly, Randolph Bank's Truth-in-Savings" Disclosure says:
"Make at least twelve (12) point-of-sale transactions on your Randolph Bank Visa Check Card... Pre-authorization transactions [i.e. transactions that haven't settled (posted) yet] and ATM Withdrawals do not count towards this requirement..."
Their web site says here
"...12 debit transactions..."
Respectfully, I think we are overthinking this and worrying unnecessarily.
ETA: I do support the idea above of "testing" some transactions first and even verifying them with the bank in case it isn't clear how they would be treated. I'm just not convinced that only transactions made at POS terminals will count towards the RCA's transaction requirement.