Regency Dress for Jane Austen Festival

I have finally decided on an outfit.
Dress. I am going make...
This one.

See link

Although will make the spencer longsleeved.
So, last night I decided to try to see if I could do a drawstring dress using the S&S pattern as my base and using the 'moulage template' to compare and adjust so I knew how deep I needed to go to fit (see I can work some stuff out myself). Oh and I made sure I added ample fabric to top and bottom of bodice just in case. I can get it over my head, the armholes don't feel like the are too far forward. Got to put the drawstring in and see how it feels next.
Now I get how to add the drawstring about the neck.
I'm confused how to add it on the waist? Trying to figure out of I should slightly gather the bodice first attach to skirt pieces then add the drawstring like on my modern clothes is like little loops the string goes through. Or is there something that needs to be done on the bodice first? Or do I just use a sash?
Haven't got enough spare fabric to do a long skirt so might do a shorter one so I can experiment.
My aim is to have a dress I can pull over my head rather than struggle to do up with a back opening. Don't want 'snaps' as they might undo. Buttons I avoid not having buttonhole option on my machine. Hook and eye again its the coming undone problem.

I'm thinking about doing this for my hair/head dress.
But having turban/hair wrap in pink and white instead of blue and white.

Quick Update
I'm wondering if I should now change design as my mock up drawstring isn't really suiting me. Plus I really aught to use the material I bought originally.