You're very welcome. We all need someone to take our hand and guide us sometimes ;D
As far as the DHCP thing goes I would say just don't use the one provided by pfSense. I have the DHCP server installed on my AD Domain Controller and all you have to do in pfSense is to configure the DHCP Relay service to point to the DC's IP address and any DHCP request that hits your pfSense box will be forwarded to your Windows DHCP server. The DHCP server in pfSense is pretty basic and I was more comfortable using the Windows one.
As for configuration recommendations beyond that it's very difficult to make any as every environment is different. What I would suggest though is to make a checkpoint of your pfSense VM before you try anything new so you can go back to a known good state if you somehow screw something up. God knows that's saved me many times. Oh and thoroughly research whatever options/services you plan to change in these forums and on Google in general because pfSense has a way of tricking you into not fully understanding the impact of every configuration item.
One thing I had issues with: by default pfSense will change the outboud port that your clients use to communicate with Internet servers, just in case two clients tried to go out on the same port at the same time. This broke a few applications where the client initiates the communication but the server always responds on a pre-determined port. In those cases, because pfSense changed the outbound port from (for example) 501 to 50001 and the server always tried to connect back on port 501, the connection would time out. Unfortunately I can't remember for the life of me the setting I changed to fix that and tell pfSense not to change the outbound port for client-originated requests. I think it might be the "Insert a stronger id into IP header of packets passing through the filter." under System -> Firewall/NAT but I'm not 100% sure. Anyway you probably don't have to play with this unless it becomes a problem.
Another hint regarding checkpoints is to delete them all once you've attained a good, stable state. Checkpoints are great but if you keep too many or you keep them too long the delta vhd that are created with each checkpoint become very big and your VM's performance may suffer in the longer term. It's a great troubleshooting tool though. Also I don't know how you do your backups but I simply have Windows Server Backup backup Hyper-V and its VMs and that works very well too. That has saved me when I have forgotten to make a checkpoint before going in blind and changing stuff just for kicks :D