I reckon you have to be careful with additives, the Ethyl Maltol in this recipe.
You're having trouble balancing the strawberry/raspberry and the almond in the marzipan.
EM will make your fruit pop but it will also mask softer, subtler flavours ... the almond in this case. So you might well go around the houses balancing if you start out with the EM in there.
I would trial a new recipe without any additives, get the flavours balanced and then decide whether you need to use EM, sweeteners etc ... they should go in last for a particular effect. When you finally add the EM you will taste the effect it's had on the whole thing ... you might well decide that it's completely unnecessary.