@4rr3n
well, additional to having my home network running with vlans for some years now without ever having trouble as @johnpoz mentioned.
I listened with a packet sniffer between vlans (on each virtual interface)...nothing but traffic that is allowed. Nothing special, nothing serious...but hey, it is a home network, privatly used...
I tried to set pfense to separate between vlans, works fine for my needs. As important: configure your switches! No productive traffic on vlan1, change native vlan to something else but vlan1, use management vlans for access from outside (or better: do not have access from outside, I do not need that...as mentioned: private usage).
jm2c: the technical risks are manageable, more common (and dangerous) are risks on level 8 in front of the screen...meaning: it should take longer to draw up a good, usable and safe network structure than it should take to configure the machine(s).
:)