WP and WPML -necessary? incompatibility?

I installed WPML after back and forth with support WPML I discover:

1) This plugin “does not automatically translate” my pages, I write each page in the desired language, and must do this for each language selected …. then do not really understand what the function and benefit of this plugin …
The theme I bought “Higend” is multilenguages ​​- then I do not know if it really is necessary to have installed WPML to make changes language on my page? Or Higned need to have installed WPML to work in multiple languages?
2) The Gallery – in the footer – disappeared from installing WPML, have informed me that due to an incompatibility between my theme “Higend” and WPML

Please, help me