Landroval was a US server even before Turbine taking over from Codemasters, so if your characters are there, you are ok and did not have to do any migration.
You are correct that it is all under one company now, but you still need to be careful buying Mines of Moria boxes, especially in the EU. there may be copies of the Codemasters boxes still floating about and they are no longer any good. The codes will not upgrade a Turbine account.
If you buy direct from Turbine or from the in-game LOTRO Store, you don't have to worry about that. Not sure what you had planned for Moria.
The Rohan expansion was never sold by Codemasters, so there is no worry on that one, either. If you buy the pre-purchase, there is only the Turbine copy.
So codemasters Moria still wont upgrade my account even though its all under 1 company now yes? I thought maybe turbine would upgrade them now that they deal with the EU accounts too.
I was just asking as I saw a copy in my local games shop for £1 haha
It is all under one company, yes, but that company is Turbine and all copies sold in the EU now should be Turbine, not Codemasters. As you noticed, some places are still selling old Codemasters copies either because they don't realize the codes are useless or because they do realize it and hope the customer won't know until it is too late.