Hi K.C., good points on the creepage & clearance.  I chose to stay away from that area due to the complexity of the requirements and rather focus on the concept.  That said, yes the design would require modifications to meet. 

FYI:
Dual Photovoltaic MOSFET Driver Solid-State Relay  http://www.vishay.com/ppg?84639
SSR Design Using VO1263 - Vishay  https://www.vishay.com/docs/81225/ssrvo126.pdf

It uses Photovoltaic cells to drive external MOSFET.  Much better in size, isolation and lower power.  

To get the rated isolation, you have to understand the creepage rules for PCB.  Most common mistake is routing tracks in between the primary/secondary side of optoisolators!

BTW: 

Watch out for the freewheeling diode inside the MOSFET.  Your SSR is only good for DC.  You'll need back to back MOSFET in series for AC SSR.