On a multi install, will the payment method/gateways be individual per theme or across the board?
Gateways would only work with each theme. Let's say you had JobRoller and ClassiPress on a multisite. Multisite will allow you to create a single login for the ClassiPress and JobRoller install. Other than that, they would both act like separate sites. Sales on one would not have any impact or effect on the other.
I see fxtender has google checkout, but is for jobroller, will it work on the others?
FXtender is made to work with JobRoller only. You would not be able to use it to enable the Google Checkout gateway with any other theme. However, we currently have a free Google Checkout plugin for ClassiPress (
http://wordpress.org/extend/plugins/...eckout-gateway ). We also have a Google Checkout (now Google Wallet) gateway for Vantage (
https://marketplace.appthemes.com/pl.../google-wallet ).
Can you add a new user from admin, so far all i see is to add existing user from network?
Yes, you can. The demos only show "Add existing user" because the appthemedemo user is not a true admin. I logged into our demos as a true super admin and created the screenshot linked below so you could see that it is possible.
http://www.appthemes.com/wp-content/...e-new-user.jpg
Hope that answers all your questions. Let us know if you have more.
Cheers!