Group Composition

Hello,

I am trying to figure out which route I should go with creating a LoTRO boxed group. I run a 5 man in WoW to run instances and want a similar setup in LoTRO. My questions are the following.

With f2p what type on money would I need to invest to be able to do instances at later levels?

Second with a duo group would I eventually be able to do the 3 man instances? 6 man instances?

If you have a 6 man group can you do the 3 man instances with all 6 or is it capped at 3 players maxed?

Are older raids able to be done by single groups?

Thanks.