The main reason I don't want to change my IP range at home is because I am a geek. I have about a dozen or two devices (depending on what you count.) About half of them are dhcp, while the other half are servers. I have two windows AD domains, a virtualization infrastructure, redundant dns servers and dhcp servers, I serve an openvpn mobile vpn server for when I'm on the road and want to VPN into my house. I have site-vpn's with other companies, where I would need to reconfigure both my pfsense, and also other companies' firewalls in order to accommodate the IP change, etc blah, etc blah.
I estimate renumbering my home to be around 1 day of work. I am, in and of myself, a small company.
In any event, I think this thread is done. The conclusions are:
At present in 2.0.5, pfsense can't do NAT before IPSec vpn, but it can for ovpn, and it might be able to do NAT before ipsec when 2.1 gets released
If I need to do the NAT before VPN at present, I can daisy chain two pfsense firewalls. Let one handle the VPN, let the other handle NAT
I was actually able to workaround, by adding a NIC to pfsense. Assign an IP on a subnet that doesn't overlap my internal LAN, and put both subnets onto the same wire. (would have been even better, if I had a separate LAN or vlan). So I don't VPN directly from the LAN to the remote side - Any internal machines at my end that need the VPN shall have a second IP address in the second subnet, and a static route to reach the VPN via this second subnet. I'm currently using this solution, it works.
Thanks everyone for your help and suggestions and ideas.