You can ediy some things but not as many as in livechat. Here you can read a little about it: https://kayako.atlassian.net/wiki/display/DOCS/Template+editing+best+practice+guide
It still looks that livechat is better. Well I think I will stick to that. But what about intercom? You know them???
well its true but still i like Zopim
Sorry I donāt. I know zopim (which i see that you also know) and OTRS.
Than I canāt use it 
I really donāt want to use it on my pcā¦ Maybe thereās some unofficial app which allow you to use it? You know something about it?
OTRS is just a free solution, right? My software really needs to be up to date all the time. Security is very veeeeeery important!
Than really check LiveChat. Or Kayako - they are also good.
Have you tried WP Live chat support?
Its actually works in PC ,
It have only bugs type thing in mobile apps !