lilkel32:

...Well, when I went into Make File, I chose mpeg-2 (instead of mpeg-4, which I thought would be best) and chose Custom.  I made sure all the parameters were the same as my original footage--720x480, 29.97 fps, and most importantly 8000kbps (I had not changed that setting previously because I didn't know what it was--it is defaulted to 6000kbps.)  That completely did it!  

 8.5mbps would be about the top quality for standard definition video.  That is also the default rate for "best quality" DVD image creation.  6mbps is medium quality, suitable for output from some VGA-grade video from small cameras, or if the light quality was not so good, and allows more video per disc.  However, neither setting would be on part with AVCHD in its original state, unless the light level were so low that the video had lots of noise and bad white balance, in which case HD is an oxymoron.

lilkel32:

Now when I watch my completed movie, the quality of the video is exactly the same (at least I can't notice a difference since I can stream both the original footage and the transitioned/titled completed movie.)  Also, knowing "it's all about the kbps" helped fix my issues with my HD footage.  Once I chose mpeg-2 and changed it to 11000kbps (my original footage was 11188 but I couldn't get THAT exact) my HD footage not only streams properly (it wouldn't stream when I tried saving it with default mpeg-4 settings) it is also the same quality as the original straight-from-my-camera footage.  

If you have a Sony AVCHD camcorder model of the type sold between 2007 and 2010,  the bitrate of the HQ setting is probably 17mbps. You'll get better quality by setting up your projects as HD and exporting to either to AVCHD-DVD disc image, whose m2ts file in the STREAM subfolder you can probably play on the PC and stream to the TV; or if you export to MP4 using a customized resolution and bitrate setting that approximates the original.  MPEG2 at 25mbps is also good, but uses lots of space.  Anything you upload to YouTube, however, will be forcibly compressed to perhaps 6mbps or less; and many YT viewers will opt to see it at the default SD setting, whose bitrate may be under 4mbps, especially if the viewers' web connection is slow.