One thing I've found strange about them Debit cards. Transactions with my card can be processed as a debit or a credit transaction at POS but still treated as a debit to my checking acct at the bank. For some strange reason the receipts for transactions wrung up as a credit are easier to read (printed with darker ink) and don't fade as fast. Now I have all transactions processed as a credit.
My first debit account was set up so that, whenever I did a debit transaction, it counted as a check against my monthly limit of how many checks I could write (I think it was 10 a month without any fees or something like that). One month I looked at my statement and saw all these check fees and didn't know what was going on, so I asked the bank branch rep and he explained how it worked and advised that I just use it as a credit card. Apparently the credit transactions don't clear as quickly since they have to go through the Mastercard payment system, but as long as you keep a ledger that isn't a problem.
You have a limit on how many checks you can write a month? I've never heard of that before.
My credit union used to charge me $5 a month for having a checking account. Then a few years ago, I went in because I had lost my debit card and they put me on the "free" account.
A debit transaction hits my account immediately. If I run it like a credit card, it takes 3 days to clear out, but the money for a credit purchase is immediately put into pending transactions.
The convenience store I frequent here in town is strange in that regard. Sometimes the credit clears before I can get to my car.Other times it takes 2 - 3 days. Same with Pending transactions(which is hit or miss also)if a transaction is pending sometimes it's only for a day one was pending for almost a week. The feds stopped the consumer from taking advantage of the "Float" years back but obviously it's still a practice for business.
I check my banking account balance pretty much every day online.

In the past, I had a hard time with checks because my apartment I lived in at the time would hold on to it for two weeks before they deposited it. I also wasn't balancing my register or checking the balances online either. I bounced quite a few checks then. Then I learned and I did this even at the last complex I was in, I got a bank check (which is free) and paid with that every month. And now, since I'm a little more grown up, I would check to see if it cleared when I did write a regular check.