Ok, so I tried Buddy's cake. A co-worker brought it in for a birthday and it was AWFUL!!! It was one layer chocolate and one vanilla separated by god-only-knows-what. Honestly, I can't tell you what the filling in between the layers was. Some partly liquified artificial chocolate something. The icing was a shortening based with a really bad after taste. Nothing against Buddy, just who is mass producing these.
Yes, you can make your flowers ahead of time, and no, you don't need to add any gum tex to them. Leave them to dry at room temp, do not put them in the fridge. You can put them in a cake box or tupperware container when fully dry to keep the dust, etc. off of them. HTH
I actually use a clay extruder I bought at Michael's. It's metal with a crank handle and works really well. It's made by Walnut Hollow and you find it in the sculpy section. With a 40-50% off coupon in runs around $15.00. Lots of discs included. Only thing is you need to warm your fondant first, then it extrudes quite easily!
I too say refund. Usually the cake is the centerpiece of the party. I understand the traffic, accidents etc, but even though it is not your fault and you did everything right by communicating with her, two hours is just as bad as not getting it there at all. Sorry this happened to you