You could, but I am not planning on doing so. Click the topleft corner of the interface if you'd like to select yourself. I'll look into the text problem.

Just skip setting a parent for the frame you're using, or use WorldFrame as a parent(but maybe that causes problems, I don't know).

Pretty much every text string in hud options is clickable, so clicking the health text string would toggle it on/off.

so you want me to implent something that doesn't work properly and you wouldn't even use it?
Anyway, with the planned changes that won't be necessary.

You don't need small target and player unitframes, clicking the topleft and topright corners of your interface does the same thing as the player and target frame.

Can't say much about the scaling, it should work and I remember it working. I cannot check it right now so there's not much more I can say.

You can make the hud fade out based on diffrent conditions, check the general options. Sorry about it not hiding when you press ctrl z, it wasnt ment to be that way.
Pretty much everything should be clickable in hud options, clicking the text header for health/mana texts should disable them.

I should have said this before, the plan is to allow you to track anything on any bar, so you could for example track your casting on the bottom bar.

Hud uses ARIALN.TTF which is located in the Fonts folder. So pick the font you like, rename it to ARIALN.TTF, create a folder in your wow directory and name it Fonts, place the renamed font in there. Restart wow if you had it running.