Bitrix24 Community

Hi - I'm trying to determine if Bitrix will be an appropriate tool for me.  I have a one person business - just me.  So I don't need any internal collaboration.  But I'd look a good way to integrate communication methods (email, chat, screen sharing, phone meetings) with external clients, as well as have them comment on things I post for them (eg screen shots).  I haven't found a way to set up users in Bitrix this way - that is, it seems internal users have access to everything - not what I want.  Is there a concept of an external user one can communicate with but not share information like time tracking, detailed task planning, etc?