Might include:
TPA Ethyl Maltol 10% and Smooth?
Hope you know the taste of your 30 ml. flavor quantities. Might be better flavors that you will like more from a different vendor/blender. Could check out low cost like Wizard Labs 8 ml. a flavor for $1.49.
When I started out I wish I only bought just enough flavors for 4 or more recipes I knew I wanted to try.
FA: Fresh Cream ,Marshmallow ,Vanilla Tahiti ,Caramel ,Meringue
Cap: Vanilla Custard v1
Wow. Thatâs a lot. But then, I have a very simple flavor profile that includes mostly fruit and candy flavors. I hate baked goods flavors, vanilla, cream, cereal, and so forth in my juice flavor. I have 8 flavors that I use to make about a dozen juice flavors. And I have no complex recipes; nothing has more than two flavorings in it.
Syringes are a pain in the butt. I would invest in a cheap scale like this one or this one
Mixing by weight means there is no cleanup, and no syringes. You just place a container or bottle on the scale, tare the scale (zero it) and add ingredients and taring the scale after each ingredient is added. Couldnât be simpler.
As for buying flavoring from one brand, I would advise against it and say you should find recipes you want to make and buy those ingredients. People use various brands of flavoring for a reason. Like I have lots and lots of strawberries. I may use one in a recipe, and use a different one in another recipe, even if the recipes are similar. Every flavoring is different. And they are used to give a recipe a specific flavor. That doesnât mean substitutions wonât be as good. But if I use Shisha Strawberry by Inawera, and you use Red Touch Strawberry by Flavourart to mix the same recipe, you arenât going to get the same results I did, because Shisha Strawberry has a more candy-like taste, and Red Touch is more of a fresh strawberry.
If you just go at this and buy flavors by brand, it will be a long time before you can actually taste a recipe the way the chef intended. You seem like you are on the right track. You are doing your research. One recipe I see that may fit your profile is Unicorn Milk. It is one of my favs and when I mix it I mix it 16 Oz at a time. Yeah, that is a lot of juice 
But I love it. And it is a real steeper. So after a couple months when it gets nice and creamy I like to have a lot left because that is my sweet spot with it and I will vape it daily at work and at home. You and I have the same flavor profile. So I am just giving you warning⌠everything you are going to want to make is going to be better after a month or two steeping. That was my dilemma when I started mixing.
As for the coffee extract discussion⌠I may have to get me some Chicory and see if I can extract that. That would be a killer coffee vape!