How do I make the Applications preference tab be useful again?

Question

Once upon a time, there was a simple list of MIME types and options of how to handle each. Sometime ago, that morphed into an example of terrible UI design and functionality is critically compromised.
For an example, see http://i.imgur.com/EViHJ.png
Here are the problems:
1) The columns can't be resized, thus it is impossible to see the actual MIME types on the left side, which is kinda important as that's what I'm mapping to apps/actions through these settings.
2) There's a horizontal scrollbar with a couple pixels of movement. That's just plain sloppy. Both the window size and the column sizes are fixed, so its impossible to resize anything. When all elements are fixed size, there should not be a scrollbar horizontally, especially not one that barely moves anything. Its amateur night on the UI team.
3) MIME types aren't even shown in some cases. The 'friendly' names are listed first, knowing the MIME types almost completely out of view. That's bad enough. Worse, some don't show the type at all! Its sorta important to see that to know just what the hell I'm setting here.
4) Plugins/apps that don't directly list the MIME type are not selectable from the dropdown. Sometimes the best thing for handling a format doesn't officially claim to do so, but I should still be able to select it. Unfortunately, I can't.
Use case where this brokenness causes a bad problem:
I want to be able to view PDf files with a plugin, not download them. Firefix 4 broke the Quartz PDF plugin that was small and efficient. At least Schubert's fat plugin got updated in response so it sorta works. Those "Preview Documents" are actually PDF and PosctScript files (funny, I never knew those formats to be Preview documents, especially since Preview.app has no native file type and makes no documents). I know the first two must be application/pdf and application/ps, but waht is the third? I thought it would be application/x-pdf, but patching the plist for the plugin to add that doesn't help. What MIME type is that really that's listed there? No way to find out, so I can't fix this problem.
In summary, terrible UI design leads to unrepairable brokenness of the configuration, which only needs to be fiddle with because Firefox broke other stuff.
Please, quit trying to make ***** ripoffs of Chrome anti-features and put some damn effort into making Firefox suck less. If we wanted Chrome, we'd use it. Stop following the idiots at Google! Tabs on top, no status bar, fast version bumps, attempts to make part's of the URL non-visible, etc are all BAD IDEAS.
P.S. The submit a question process takes a half dozen screens of clicking through crap before I can type. The questions are dumb, the suggested 'existing answers' are even dumber.
P.P.S. Your forums ***** suck. Half the line returns I used are gone when I submit. When I edit, everything displays just as i entered it. Go back to viewing it and again some line breaks are missing while others are there as typed. How the hell do you break something so simple?
''Edited by a moderator due to language. See the [http://support.mozilla.com/kb/Forum+and+chat+rules+and+guidelines Rules & Guidelines] .''

Answer 1

I don't seem to get any tooltips. Even if those worked, it doesn't excuse the overall awful design of the UI here.
The plugin for PDF (and postscript) lists two MIME types in its plist. I tried adding what I think the third should be and restarted Firefox, but it still doesn't list that plugin as an option. There's really no excuse for not letting me choose the plugin if I know it'll work. What's the point of the interface if not to let me do just that?