finderkeybindingskeyboardnavigation
I don't like the default finder navigation shortcuts command-up, command-down because you need to press 2 buttons instead of 1. On windows, delete leads to previous folder ("back") and enter enters the folder instead of renaming it like on the mac.
I have already tried in system preferences but mac os won't let me enter delete or enter as a valid shortcut key.
Thanks
Any person new to Apple and Mac would find lot of things un-intuitive or just forced on the user, w/o any options to change it. Or it might be that just many of us had their first experiences on Win/Linux systems.
But just found this plugin to finder XtraFinder which among lot of other options allows you to ENTER/RETURN to open a file.
Feeling a lot relieved now! Hope it helps.
Because tab isn't a modifier key (like command, shift, option and control), you can't use it in combination with other non-modifier keys to make a shortcut. It's simply not possible the way the OS X input systems work AFAIK.
You might be able to jury-rig something together using KeyboardMaestro or similar apps that listens for tab-return and then executes the send mail command, but I don't know how well it would work, or how closely it would match your expected behaviour.
Best Answer
Check out Keyboard Maestro http://www.keyboardmaestro.com/, it should do what you want. I know it is not exactly cheap for a utility app, but it does a provide a huge amount power beyond simple key remapping, and it has proven to be stable across many Mac OS X versions.