Hello, I am new, questions about compilation and testing, to be a developer.

[Maurizio Galli [m4u9]]

Hi Manuel,
I'm in the openSUSE Xfce development and packaging team.

 > 3.- I use xfce as my main environment, from the openSUSE 
repositories, how do you test the gitlap version completely without 
interfering with my openSUSE installation?

You can test the development version of Xfce by adding the RAT 
repository [1] or using our VM images [2]. Both are built using 
Tumbleweed as base and Xfce from gitlab

[1] https://build.opensuse.org/project/show/X11:xfce:rat
[2] https://en.opensuse.org/Portal:Xfce/Images

Feel free to contact me for openSUSE specific questions if you like, and 
we could use additional help in our team if you want to contribute there 
as well :D.
Best,
Maurizio

https://en.opensuse.org/Portal:Xfce