I have taken this class and enjoyed it, lots of different techniques. The filigree cage can be made beforehand as it is made from royal icing. Just make sure you store in a safe place as it will be fragile. HTH.
It's funny how some of us think that just because you buy food from a legal, licensed place it is germ free and everything is totally hygienic. I was in a supermarket and saw the guy in the bakery section scoop cake batter into sheet pans with his bare hands, hairy arms almost up to his elbow in a pail , it really grossed me out. I don't understand why he couldn't use a cup or ladle.
I don't think it is the pans,I only use convection for cookies so that they bake evenly and crispier. Most ovens have an option for bake (normal) and convention.
The other reason could be the baking powder or whatever raising agent you used.
I think vintage themes is something that was in style more than 30 years ago, I could be wrong. From what I have seen when decorating there is a lot of wooden stands and frames and chalkboards used.
Here is a link to one of Amy Atlas vintage party for a boy, her blog will give you some ideas. HTH.
If you don't have an airbrush could you not just use a soft paint brush and dust some darker red over the roses to give it a darker tone?, it might be better than the soft pink. Your cake is beautiful.
It would be a shame to toss your gumpaste , use it for rose, peony, magnolia centres and also you might be able to use it for orchid centres. If you made a lot of the gumpaste divide them into smaller packs, wrap well, place in ziplock bags and freeze for future flower centres. I think you will not be able to salvage it for flowers, it is not worth the aggravation.
Here's a couple of good videos, I just posted for 'terrified of ganache'.
Here's a couple of good videos.