Suiteable output for the web

Hi everyone. I have a series of videos that I will be posting to the web in 4 sections. As far as I know, we will be hosting these ourselves, and people with a variety of connection speeds will be accessing the videos. I am going to tell you the specs of the original video I am using as a test piece and then asks some questions.

Original Video:
720 x 480 (.9091)
29.97 fps
48000 Hz Compressed Stereo
6 Minutes and 45 Seconds long

1. For posting to the web, where should I focus my trimming back -- frame rate or bitrate? I did a test video with a framerate of 15 fps and a bit rate of 1 Mbps and a max of 1.5 Mbps. I left the audio at 192 Kbps, and it sounded good. The video looked good too. File size was 59 MB.

2. I made another version of the same video at 30 fps, but dragged the bitrate down to 233 Kbps and a max of 320 Kbps...and the video looked terrible if there was any movement. I took the audio down to 56 kbps, and the audio still sounded good. The file size was around 16 MB.

3. We will end up posting hours of video, probably broken up into 4 different sections, so we can keep the file size and low as possible.

4. Forgot to mention, but I am using the H.264 output, which gives an MP4 file.

Does anyone have any other suggestions for reducing the file size to keep the quality?

Should I reduce the resolution? I kept the video in its native resolution of 720 x 480.

I am using Premiere Pro CS4. We aren't adding any animations, and the editing is real basic -- just chopping out the parts we don't want; no image stabilization, color correction, or anything like that. Not sure if any of that matters.

Thanks for any help you can offer.

Ian