I'm just curious how much of a security risk (and performance issues) it is to have all of your tables (more specifically listed below) in only one db on your server.

I am going to be storing information for clients (private info requiring SSL and encryption), admin info, page information, forum info, quote information, etc.

I am guessing that it would be ok and that the primary concern is the fact that the more queries being run against the db the slower it is. So if you have many types of information hooked into the database there is going to be a lot more use on it.

Just curious on thoughts (for background: the system is on a VPS so I am not necessarily worried about the risks of shared hosting and I am anticipating up to 30 users at any given time).