The IM module is for managing inventory quantities and value in detail.  If you don't want to do that, look at Miscellaneous Items (in the CI module).

You might want to set up a call with your Sage Partner / reseller, to discuss your requirements. 

 Yes you have to. Just make them all Finished Goods.  Many people do that.

Indeed.  Raw vs Finished is a meaningless designation, only controlling some report selections.