Beev,
You asked - Do I need a generator in my Class-C?
The absolute answer is NO.
The real answer is that the additional cost is well worth it. If you don't even think you will ever dry camp, it is still worth it. It will only take one weekend of not having A/C or being able to use the microwave when you or DW wants to make it worth having. Most of our lives in this coach, we have put maybe 10 hours a season on our APU. I always felt stupid changing the oil in the spring. But we were at a special gathering this last summer and it was HOT. We put 38 hours on the APU between Friday afternoon and Sunday noon.
If(when) you go to sell this unit, it will sell much better with an APU installed. Just take care of it so it stays running.
Added: APU = Auxiliary Power Unit - a generator to most folks
Matt