1. promo offers only apply when you spend x amount in x amount of time. But still, you get the $150, woohoo. And it's a one time thing. Plus you can get this offer (usually more) for opening a checking account with direct deposit going into it.
2. cash back, the best you can do on all purchases is 2%. Enjoy your $100. You can use the rotating cards to get up to 10% but then you have to target spend, which makes you spend more.
3. Building credit is worthless. I got a 30 year mortgage at 3.6% last month with no recent credit. And that's the only credit I'll ever need.
4. My debit card info has been stolen 5-6 times in the last 5 years. Never had to pay a dime.
5. How many times have you used that? And I just checked, my visa debit card has the same feature.
6. My bank does foreign exchanges at better rates than any credit card I've ever seen.
7. Until the power goes out, internet goes down, computer system has a glitch, etc. then cash is all they accept.

My projections are based on the average prices for the average American. Some will do more, some will do less, but most people will be right in that range. If anything they're overstated, I rounded up on everything and had them spending all of their disposable income. I'm a finance guy too, and I've been at this a lot longer than you have.

Let me guess, you work at convergys and "sell" credit cards (or IBCS). Am I right?