Until data caps become a reality on Verizon, it makes no difference whatsoever whether you're using wifi or 3G. In most cases, wifi will be faster unless you're using using dialup or crappy dsl. When using wifi, data is using wifi. When using 3G, data is using 3G.
I don't know what you're talking about.
To answer the question, wifi does not count towards your data usage per your wireless carrier. Using wifi is the answer to the tiered data. Also, the tiered data usage probably won't come into effect until 4G is introduced. The Verizon CFO said that.
Sent from my Droid using an internal neurocellular processing unit