I am pretty new to SSAS and have two very basic questions which are confusing me.
SSAS only supports windows authentication, so you need to be on the same domain in which your SSAS server is, so that you can connect through windows authentication to the SSAS server, if this is not possible then you will have to install it locally.
You cannot have an instance of SSAS to be both tabular and multidimensional, but you can have separate instances installed on the same server for both multidimensional and tabular.