Formal Entourage.
If I have multiple entourage's in my hand and play a lord or lady can i play all the Entourage's or is it on a 1 for 1 basis?

Also, Castellan of the Rock.
If I have 2+ of them in play and play character or location, do I kneel 2 characters or again is it 1 for 1 or do I still only get to kneel 1 character as it is 'Limit 1 Limited response per round'?

(I've just been given a mass amount of Lannister cards)

I'm not seeing a great point in having 'Infamy' in most instances. Could I have some advice on how to use it well?

Cheers again guys, you've been a great help so far

Royal Entourage: you can play 3 if you have them in hand/discard pile. They're 3 different cards, meaning they are different triggers.

Castellan: it would be the same as Royal Entourage only if it didn't have the Limited Response. Only one Limited Response per round means you can only trigger one Castellan per round (and forbids you to trigger other Limited Responses the round you used the Castellan, mind you).

I just want to add to your Q about infamy: It was designed in CCG and back then it had more support and bigger meaning. Now there is not much cards with infamy and you do not benefit so much from them specially when there is always a possible thread of Valar. The best it brings when you play it is that you can protect all power from being "stolen" during power challenges from your House card.

Also you should note that in the new FAQ was Alchemist Guildhall made a Limited response too. So if you trigger Castelan in the marshaling phase you cannot trigger the AG response that round anymore.

Also with Castellan. Can he count as the character it requires for his effect? Or would I have to wait until I bring out another character? Reason I ask is like with a lot of shadows cards it says "when a card comes out of shadows" and can count themselves, so I would understand it as I could use the ability even if he was the only character I could purchase that turn.

Cheers guys!

That's correct. You can play Castellan of the Rock and use his Response rightaway.