Sugestions:
1. Higher end acessories: Jyarz, Cvault, Boveda Humidipacks, good grinders like santa cruz shredder and spacecase
2. Bongs and bubblers for water filtration, also some adapters like male-male adapters, a sherlock adapter, some ashcatchers, etc
3. Lose the low end models which just make people turn away from vaping like Eagle Bill, Vapo2, Vapir Oxigen, VaporDaddy and Vapir Oxigen
4. There are a couple new units that should feature there like the Lotus, the Hammer, the Pinnacle Pro, and the Firefly and the Versa (since you don't have 7th floor models anymore).
What i find most annoying in EU stores (not just Vaposhop but your direct competition as well), is that i can't get everything in one store. I need to get a bong in a store, a male-female adapter in another and a vaporizer in another.
I'd like there to be an EU store that is about quality products and diversity, and where i could buy everything i need, from glass to a container to a vaporizer.
I can't do that in an EU store. Well, everyonedoesit is the one with most choice but it has less choice in vaporizers and it's more expensive.
About the site itself, and the design improvements. I like it a lot, nothing to add on that front.
One thing, i would try to create some sort of guide for the new comers. Before i found FC i went to your store and i had no idea where to start, this is, again, something that is a problem in every store but a simple guideline with a classification in several variables like autonomy, flavour, durability, size, stealth, etc... would be a tremendous help for someone new to vaporizers.