Hello,
1) No, but you have transaction logs to check subscriptions. Also, I think it would be better to rely on the payment processor you are using to get notifications, most of them will offer this service. There is also
this, but I am not sure it is vB 3.7 compatible.
2) Yes, if you want to. Otherwise you can change their forum permissions. Try to set a sample subscription, it is the best way to get started