[Jerry Rio] "So try increasing the bit rate...by how much?"
I would increase it in increments of 500,000 Kbps until you can't tell the difference or reached your desired file size.
[Jerry Rio] "Also can I use the audio in the MPG4 file or should I render the audio separately like youtube says to in an mp3, "
Use the audio in the AVC file. It's AAC audio and will sound great.
[Jerry Rio] "And if I use the audio in the Mpg4 should i set to 4800 instead of 4100 or will that not make a difference. "
I always use 48,000 for all of my audio as this is what most video cameras use so chances are the original audio is 48K. That's what I suggest you use.
~jr
http://www.johnrofrano.com
http://www.vasst.com