It sounds like you are thinking of a mill, not a router. They are really 2 different machines. The router will be able to handle the wood and plastics; aluminum if you build it very heavy. But there's no way it will do a job on steel that would impress a machinist (although it might make some impression on the steel). That 2.2kw spindle should stay with the router - it's much too fast for steel. And I've never seen a router with automatic lubrication, although it's a common feature on larger mills. It sounds like you may have some of what you need to build a router, so if you've got room for two machines, keep your eyes open for a used CNC mill with an obsolete controller that's suitable for retrofitting.