Is this the firewall software for me?
I have already installed a fresh FreeBSD on my old PC.
I want to install a firewall system with some gui where I could manage it remotely.
Can pfsense do this? The impressions I get from the limited docs here is that you just boot it up using liveCD or CF and you will go into pfsense.
But what about an installer where I could install pfsense into existing FreeBSD? Cause I want to run other services like ftp proxy and squid on the same server. Would it be possible?
No, you can't install pfSense on an already installed freebsd system. pfSense is a customized freebsd system. It's a ditribution, not an addon that you can install on top of your setup. However you can install custom stuff after you installed pfSense to your hdd (the livecd has a installer feature). This is either supported through the webgui by adding packages that are available for pfSense or from the shell. However, everything that is not available from the webgui packages section is not officially supported.
oh..that means I can install pfSense into an empty hdd and then install more stuffs from there with port command?
Yes, but it's unsupported deep water with no lifeguard ;)