And now that you have a new thread for mwan3 questions, maybe we should close this one given that the original issue (WAN + LAN on one port) has been solved. If you want to continue with guest network stuff, start a new thread on that -- feel free to tag me in and I'll continue working with you on that.
If your problem is solved, please consider marking this topic as [Solved]. See How to mark a topic as [Solved] for a short how-to.