You wrote: I find the cumbersome way Ubuntu handles file access to be the
most painful and frustrating of all Linux "features"

What does this mean? You blame it on Linux, but that is only the kernel. It
can use many different file systems, ext3, ext4, Reiser, btrfs? Is it
permissions or what?

I think I nailed it down. It is the fact that Linux lists all its devices
whether they are connected or not, effectively hiding it in a forest of
potential. Also, my movie player apps will not "See" the hard drive if I boot
from the USB. They never give me to option to open a file on it or read the file
list on it, or browse to it.

It is likely a permissions issue. Kubuntu and Ubuntu use AppArmor for
security and recent versions of both have tightened control. It depends on
the file system format and how it handles permissions about how many hoops
you have to jump through.

If it is formatted FAT32 all you have to do is open it and it will
automount. Once it is mounted you can use it in any application.

If it is a Linux file system things are tighter. You will have to provide a
password if the file system was created outside of your user space. Or you
can change the permissions so that it has you as user and users as the group
with full write access.

The other thing that sometimes confuses people is if you open a file manager
as root home will be root's home and not your own. You will have to navigate
to your own home. Also any changes that you make will only be available to
root unless you change it to your user name and change the group
accordingly.

I have KDE set up to mount my partitions when I login. It prompts me for
passwords for my ext4 data partitions. It is a bit of nuisance up front, but
it allows me to use all of my partitions without any delays or
inconvenience.

In GNOME I just wait until I need them and then click on the partition and
it will ask for passwords as needed.

If you don't mount them then they will be unavailable to you in applications
until you mount them.

I may have miss understood what you said here so bear with me. Booting
from the USB may be your biggest problem. The image on the USB is
handled in a different way than when a Linux distro is installed.
Intentionally you are not allowed to distroy files on the HD by
overwriting so the installed OS can't use the hard drive. I have not
likely presented this information to you to make it easy to understand.
What is important is it is likely a permission thing. When You start the
OS from a live CD you are told that your work won't be saved.

I wonder how many times you have tried using other OSes like Windows
from a live CD or USB. Other than specific tasks you would or are
limited to what you can do with such disks like resetting a password.
The file system is really quite simple when you take the time to view
the logic. I would suggest dedicating some of your HD to install linux
before you claim Linux falls short in the filing system area.

My external USB drive has any movies I am working on on it. I drag and
drop what I will be working on onto the desktop to speed up disk access
to the file. When through, I copy the file onto the external and it is
updated by over writing with the newer file, or re-named with "save as"
much the same way I used windows before I knew better and migrated to
Ubuntu.

I seem to have permission, it is just a pain in the ass to
locate the files and change the file names in the default screens. It is working
with USB boot once I locate them.

How do I change the default on this to read and write from the HD instead of to
the USB Desktop etc?

I always log in as root temporarily and then its simple to change permission

I have managed to locate the files but can't find a way to change the default to
look there first. So, I have to keep doing this now every time I save a file or
try to access one, seems like.

Remembering where a data file is located is the responsibility of the
program requiring the file, not the OS, so have a look in the settings
for default locations in KDenlive.

BTW - the version in the Ubuntu repository is apparently deprecated so
have you gone to the KDenlive web site and got the latest one ?

No, I had to borrow a computer/internet connection to download the one I have.
Also, the audio is not working on MP4s that are my input files or anything
really. I don't seem to have audio in Kdenlive but its output files will play
just fine with audio in Xine or other players. I dont' seem to know what audio
codec to select in setup as MP4 isn't there MP2 is and acc and PWM16bit
thingies. Suggestions?