1) Can PCs take Peer as they see fit, or is it something that must be agreed upon between the PC and the GM? For instance, could one of my players take Peer (Adeptus Mechanicus) three times?
2) Contact Network allows a character to use Fellowship instead of Influence for requisitions. If they explicitly mention requisitioning something from the Adeptus Mechanicus and have Peer (Adeptus Mechanicus), do they get a bonus to the requisition test?
My thoughts are:
1) only allow players to take Peer (1) with a group if it ties in with their background. To take greater than Peer (1) or to gain a Peer which they haven't yet associated with, they have to get the GM's permission. This usually comes about after interacting with said group during an adventure or by spending downtime to gain connections. Greater levels of Peer require greater deeds to be completed before they are available.
2) For items specific to that faction, Peer would apply.