I'm considering a 7100t model. I've had the 8700 in the past and was pleased with everything but the large size. Does the 7100t have the same basic productivity/functionality (email from private accounts like Gmail, BB messenger, browser, etc) that the 8700 has?

Yes, all BlackBerry devices have the same basic functionality. The biggest difference you'll have between those 2 devices is the smaller keyboard on the 7100t.

Some people love SureType, and some hate it. Personally, I love it and can type a lot faster - for 95% of the words I want to type. For words that are not in my 'Custom Dictionary', it can be a pain to type them the first time, but after that they are easy to type.