I assume you're talking about the governance built into the Ethereum POA on Azure solution. Each member on the network gets to deploy and control their own infrastructure. We make it easy to connect each of these sets of nodes. The reason each member has multiple nodes is to provide a highly-available representation on the blockchain network.
Does the party who launches the blockchain consortium instance on Azure have more "powers" than invited members?
Just by deploying your nodes and connecting to the existing members, you are now syncing and validating every block on the network. If you want to start being a block-producer, you must be voted-in as an "admin" on the network. As an admin, you get the ability to vote for or against other admins, and can assign your nodes to product blocks. All admins have the same power on the network.
Can an invited member add more peers or remote nodes than the rest of the consortium, and then perform something like a 51% attack?
Each admin can only assign the amount of block producers equal to the first admin on the network (whoever set up the initial deployment). For example, if the first member deployed four nodes, each member that joins can only add up to four block producer nodes. They may deploy more than four nodes, however, the remaining will simply act as transaction nodes on the network (not produce blocks).
Can fees be split between consortium members?
Transactions are free in POA networks so Ether doesn't have a real purpose. There are other mechanisms more suited for identity based networks for controlling bandwidth allocation. See this section of our docs for more details.
