There are overstay fees depending upon how long you stay in the DR, not just the $10 entrance fee if you overstay. How long do you stay each time?
And technically you could be deported or not able to enter the country again at some point in the future. I think both of those are unlikely.
I think you can have a bank account with a passport, but there may be some things that are harder to do without residency. Having residency from day 1, I really don't know what those other things are.
One big benefit is that as an incentive for retirees under this program you dont pay for the transfer tax on the first house you buy. This benefit alone, if you are going to buy a house, is worth the price of the residency! Unfortunately my real estate lawyer did not know this so it looks like I am going to miss taking advantage of this. Humm... just a thought... is there a website where I can check what date the transfer tax was paid? I believe the office is called "direccion general de impuestos internos" but I fail to figure out how to navigate it to get what I want! Anyone?