Your comments

I understand your point but not agree with it:
  1. When you register you get ST 1.4, an already stable useable product. Sure ST 2 is better (otherwise why the need for it) but right now you already buy something real and not the development of a future hypothetical product.
  2. Development takes time and money. Why don't give money to help finish quickly a product that you like. If Jon (the only person behind ST) stop working on it, you will never see a final build. Sad. This economic model work great when people participate, look at Minecraft.
Don't agree.
ST2 is my main editor for months now, ST2 dev builds are what other companies call final build.
Never had any problems with it.

When you buy a license, you get a license for ST 1.x and get a free upgrade for ST 2 as bonus, including the current dev builds.
The future of this product is sunny and the license reminder not very annoying.
So open your wallet and give this product the money it deserve.
Didn't understand what you want here...
Like Jon said, save_on_focus_lost already exists and must meet your requirement.

With this settings, every time you change the edited file or ST2 lost focus it save the current file.
This mean that I don't see a way to have a not saved file other than the current one, and it will be saved when ST2 lost focus.

This settings look useless...
Just try it again on the same config as you and happen to me.
What you want is a clipboard-manager that remember items you put in the clipboard.
On Windows you may try ClipX or Ditto.
Clipboard-manager has the advantage to work system wide, and not only on a specific application.
Doesn't happen for me with ctrl+z but does with ctrl+u
Oh yes forget about renaming in tmLanguage.
Something in the documentation about importing bundle files from Textmate would certainly help a some people.
There is one available in textmate:

But check your theme if the scopes for diff are there (check with Twilight theme)