I love the concept of the retail store and can't wait to visit it once it opens.
The one thing you must have is knowledgeable staff members. There is nothing worse than walking into a store, asking for something specific and having the clerk try to sell you the most expensive item in their store: especially when it is not at all what you asked for. (case and point- I walked into a tea retailer and asked for a recommendation; I wanted a floral and delicate jasmine tea and they had 3 different varieties of jasmine tea. However, the vendor then tried to convince me to buy white silver needle! needless to say, I walked away empty handed.)
So please, when hiring for positions, please choose people like your representatives at the International Housewares Show in Chicago.
What customers want (contrary to what they may say they want) is perceived quality. There are plenty of less than stellar coffee shop chains (which I will not name) that serve mediocre coffee at best. However, people perceive them as being great- so they will pay more and stand in line for their perceived quality. I think the way your concept is structured will help get the point across that adagio is a fine-tea provider that focuses on quality tea and not a local hang-out that happens to sell tea.