It is not ready for Joomla. I tried for 2 days to get civiCRM installed without success. I tried with 2 different hosting services. I had the services make the necessary php changes and am still not able to get it installed. The forums have many posts of others have have experienced similiar problems trying to get civiCRM installed with no real solutions, easy to implment soultions.
This tool is not ready for Joomla. Before adding any new functionality the development goal should be to make the install straight-forward and simple.
I have done several websites using Joomla and have never experienced as much frustration or as many issues trying to install a component. Save yourself hours to days of frustration and avoid civiCRM until install issues have been fixed.