Toggling between two spells & other questions

[Freddie]

HotKeyNet ... Is there any way to "toggle" between two macros?

You can toggle between two macros (or between any number of any pieces of code) with <Toggle>.

http://www.hotkeynet.com/ref/toggle.html

I believe that macros cannot be edited in combat, so is there a way to store variables in either keyclone or HotKeyNet to create a "toggle" function to choose between two keymaps?

You can create pseudo-variables in HotkeyNet that store state and cause a hotkey to do different things depending on the state.

The first is, what keys are available other than [modifer] + letter? I've heard of some issues with modifiers in combination with numbers, F1-F12 keys as well as numpad keys... Are there any keys left over? (I wish to retain the ability to type with multiple characters)

If you temporarily set Windows to use a non-English language and non-English keyboard layout, you can bind non-English characters to the left side of WoW's key binding screen. They remain bound even after you switch Windows back to English. I've never seen a post here (except for an earlier one of my own) that describes this technique, and I don't know if you will be able to trigger the bindings, but it may be worth trying.