Options = always good
As someone else mentioned, I'm also on a business account, so using Google Checkout is the only way I'd be able to buy apps. I was ecstatic when I got my Droid and found out that was how you paid for apps and not through adding the cost to your VZW bill. So, yeah, I think this is great as long as GC remains an option....
They do not normally refund game purchases, if you make a good enough case about it, they may, can't make any guarantees.
Most developers have some kind of return policy on the market anyways, they range form 24 hours to 30 days. Pretty cool stuff.
I think this is a terrible idea unless its a feature you can activate from your account and not your phone.
I just went through a situation where my son unintentionally purchased Need for speed on my phone and my wife's phone to the tune of 19.98. I was told by the CSR that I am responsible for the charges and that I shouldn't let my son play with my phone anymore! (despite there being 100's of kids apps in the store)
Anyway, to make a long story short, I don't have a problem with the option as long as it can be disabled. I like options, that's why I have a Droid after all...
Note: I ended up getting a credit from my local store manager. Its a good thing too as I am still in my 30 days and was about to go back to my BB or cancel my service outright.