XF 1.2 Create template in 1.2


First, i do not speak very well English, sorry.

I'm trying to create a new template with the new system TM 1.2.

What would be the best way to create a template?

Doing visual (style) changes in extra.css? Is this optimal? (Using TM)
I have seen that changes in extra.css are written at the end of styles.css file so, if i add all css changes in extra.css any person can steal the code and paste into your extra.css and also i need add !important on every part of this CSS to work.

Regarding the new system.

I tried changing this:

#moderatorBar {
background-color: @primaryDarker;
border-bottom: 1px solid @primaryLightish;
font-size: 11px;

for this:

#moderatorBar {
background-color: @anothercolor;
font-size: 11px;

And nothing happens.

I'm going crazy to make this changes i think xD.
Exists any guide with the start steps to use TM system?
Ok but if i edit the css templates and xenforo be updated, this css template becomes to obsolete?

Maybe my problem will be: I dont know how works TM system xD.