I am an owner of an HTC Inspire 4G. I pay $15.00 a month for data. If I had bought the HTC Freestyle, I'd still pay $15.00 a month for data. I realize it doesn't require a data plan, but realistically, you'll want to have one. Otherwise, you might as well get a simple flip phone and be done with it.
As for the phone price, I bought my Inspire at the no commitment price, so the Freestyle would be $100.00 less. The huge decrease in functionality, in my opinion, wouldn't be worth saving $100.00.
Nice feature phone (HTC's Sense UI rocks), but ultimately not worth it.
the reason why Opera Mini doesn't work is simple: this phone is based on Brew, which is like the enemy of Java. Opera Mini is written in Java and requires a good JVM (except for a couple of native ports).
personally, I would not buy ANY phone that did not support Java... particularly a dumbphone... you got to have Java on a dumbphone -- no other way you'll get decent apps. Brew is too limited...