FTP - Web Server

I want to run an FTP server.

From what I have read I need:

A port for instigating an Active FTP connection.
A range of ports for Client side PASV connections.

TCP-Incoming: 21
TCP-Incoming: 1024-65000 (possible!)

An open port is an open port (?) and since Comodo does not control port access dynamically (To open a port when a trusted application requests the connection). I would like to open as few ports as possible.

A far as ports are concerned since an open port is an open port (?). Even with only one port open does a firewall become no more than an inconvenience (hacker/trojan)?

For a given amount of traffic how many ports would you open for PASV?

I would also appreciate suggestions for firewall / Web Server setups, as this may be useful as well.

Thanks!