Firstly if the subscription fails then there is no way to manually input a payment. We have had several payments fail (around 25%). One of my members manually sent a payment via paypal however there was to way to enter this. I have had to set up a cheque payment option and get them to sign up to this.
Secondly it would be nice to be able to automatically add a colour to their username once they have signed up to the new group. This would encourage others to sign up.