sharepoint membership FBA users and groups isolation

Hello

using sharepoint foundation 2013. 

After configuring FBA with membership and role manager i have some questions/issues:

There is a way to use simplemembership instead of membership with SQLprovider?

there is a way to isolate users and groups from each site collections? i mean if i have users and groups for one site collection there is a way to be this users and groups hidden from the other sites collections?

recommended solution for sharepoint 2013 to manage users and groups in a membership database?

URL for understanding how sharepoint uses ApplicationID to register to the membership application table, (mainly to share users and passwords with other asp.net applications

Thanks