WordPress.org

Do I need to set any parameters?

Nope, you can simply use [shorturl] to insert just the short url.

Does the order of the parameters matter?

Nope, you can use the optional parameters in any order - just like for all shortcodes.

The labels added by the parameter "txt" suck, what can I do?

You can define the labels in the "Short URL" Settings page, which can be found in the "Settings Box" in your WordPress Admin Interface.

What is that "short" option for?

It defaults to "1", so by default the Short URL will be displayed (thats what this whole thing is for). But maybe you want to post your permalink at the beginning of your article and the Short URL at the end, so you can use the shortcode twice - the first time with short=0 and full=1 and the second time without any options.

I found this plugin very useful, how can i show my appreciation?

Spread the word and maybe write an blog post on this plugin with a link to the original post at the autors page.