Need to think about this a bit.
1) As for "A salesman did tell me that a firewire would be better...but from what you've said that doesn't sound right. USB/firewire...they are still just transfering the file to wherever without compression. The compression takes place in the editor or the internet viewer." Lets explore that.
In the consumer camcorder environment, firewire (DV, IEE1394, i.LINK - all the same thing) provides connectivity between a miniDV (or Digital8) tape based camcorders' DV port to a computer's firewire port. The DV (or HDV) video is compressed on the tape. When the video is imported, it is decompressed and brought into a file format the editor can deal with.
2) There are no consumer flash memory, hard disc drive or DVD based camcorders with a firewire connection. JVC used to make a HDD consumer cam with firewire, but it was short-lived. Pro grade flash memory (JVC GY-HM100, Sony HVR-Z7, Panasonic AG-HVX200) use firewire - but they do not save to consumer mpg, mod or tod formats. External pro-grad hard drives (Sony; Focus Enhancements FireStore) also connect using firewire. Other than the Red and Silicon imaging camcorders, there are no "internal" hard disc drive camcorders (and certainly none that save to consumer grade mpg, mod or tod formats.
3) Generally speaking, USB connects a consumer grade flash memory or hard disc drive computer and the video data files are copied over the USB connection - no importing or decompression has yet happened, merely a file copy activity. They are just large "document" files. When pulled into a video editor or player, that is when the codec kicks in for decompression into a format that the editor or player can deal with. Sometimes transcoding is needed before this happens. I would transcode first (using something like MPEG StreamClip) to something more useful. Windows likes WMV files. Windows and Pinnacle should be able to deal with AVI or MP4 files. After the transcoding is complete, bring the converted file to the editor or player... or even upload.
3) "higher quality on the front load the better on the back side." I agree - to a point... If the backside gets a huge amount of compression, then the video quality in a large window viewer can still be poor.