1. is it possible that the registration of registrants in the various groups in different fields to fill in, but the site is not registered in each field to see visitors? For example, one group can upload images to the gallery, the other not, but all visitors can see the photo gallery
Yes, you can set the upload quote based off subscription for profilegallery from 0 (set default as 0) to XYZ based off subscription. This would result in subscribers only being able to upload. This can be done quite easily with the CBSubs Fields integration.
2. a fully integrated credit card payment? or what tasks are still to this payment method to use for registrant? for example, should this contract with a bank? how come my account the amount paid?
Don't understand what you're asking. CBSubs uses payment gateways such as Paypal, Authorize.net, 2CheckOut, Ogone, and PostFinance (Swiss). They all support credit cards of course. You would need an account with either of those providers in order to accept payments.
3. Invite your friends pluggin be taken separately or included in the CBsub
CBSubs has no invite feature. It is a subscription management extension only. As for invites you could use incubator project CB Invites.
krileon
