To my first glance and then a longer second glance, I can say they look delicate. Which I think is the biggest bummer in flowers - well, at least from a viewing perpsective. Thick bulky flowers DO NOT look natural at all. I'd say you're doing good.
I think they are pretty. Anyone viewing the cake with little sugar flower experience will think....those are pretty. I can picture them clustered together...all the different little delicate varieties. Pretty.
As far as technically correct & construction issues...look to the PRO's. I know how it feels to want it how you see it in your head & can't quite live up to your own standards. Hope you get the help you want. I still say - they are pretty.