Hi: I just have 2 small questions:

1- I have a master and several slaves, I would like to know if when I install a new component or feature on the master (for example a new text editor), it is replicated automatically to all slaves (that will see the changes immediately on their administrators), or if that change will start to happen once a new slave site is created?

2- I need all the admins of the slave sites (which are set as “administrator” as explained on the manual) to at least have the possibility to change the templates on their sites, but not to make other great changes (like installing components). Is there a way to do it without having to modify Joomla core files?

Thanks in advance... dglite

Q1) NO it is NOT replicated automatically.
The website are independent and you have to re-install the extension on the slave site.
There is an exception concerning the installation of the languages and the themes (template) that are automatically available in the slave site because they does not save any information into the DB.
I am currently working on JMS 1.2.x that would provide some facilities to replicate the installation in several websites. All will depend on the results of my tests.

Q2) I thinik there are extension that allow give more specific permissoin and privileges on the category of user but I have not experimeted personnally.
All I can tell you is that with JMS you can give specific themes (template) directory for each website and let the administrator of the slave site to install their own themes (templates)