I totally agree that there is much to TextMate that doesn't meet the eye. Or things that are just difficult to remember. Such as keystrokes for various commands. My biggest frustration with TM is keeping track of all the modifier keys. One way to reduce the complexity of FINDING what you want is to have a search function. Something spotlight-ish.
We already have Cmd+T and Cmd+Shift+T for search-as-you-type for files in a project and symbols in a file. I'd love a key that would present a search window for searching through bundle command/snippets/ macros. It would search as you type and would display any available shortcut key on the right to help jog your memory.
The list could even be ranked in order of applicability by examining file type and scope with extra weighting based on usage. THAT would rock.
Also, for commands, I could even see typing a space after the search abbreviation-- then, any arguments entered after the space could be fed to the command as actual command line arguments. For example, typing "svnc" or maybe "ci" would find the subversion commit command. Then follow that with a space and the rest of the line might be the comment to log for the commit.
I think most of us aren't afraid using a keyboard at a command line... so why not leverage that? Sometimes it's just easier than navigating pages of menus and complex toolbars.