m-l-m, my best wishes to you. A great question and a wonderful idea!
In my experience, I think a Sephora style store would be wonderful but I'm not sure how much waste that includes and whether that format is feasible for a small business (if in fact, you're speaking of a smaller business, a "shop"). It would carry a lot of the mainstream brands but also a lot of classics, hard-to-find, and discontinued items for the serious hobbyist. Ultra luxury or niche brands would be great but aren't a necessity for me personally when I visit a perfume shop--the classics and htf are.
HOWEVER, in my humble opinion, nothing is more important than a knowledgeable and enthusiastic (not pushy) sales associate. This person MUST know about the individual brands carried at the store, and ideally should know about the notes of each fragrance OR AT LEAST have resources available to refer to. In other words the sales associate must seiously be interested in fragrances. Just this part would make a fragrance store unique in today's market LOL!
This SA should be respectful of the customer who IS MORE knowledgeable than he/she is, and should be able to take a hint when the customer proves it and needs to be left alone to explore.
The customer must be able to sample as much as needed even without a purchase. I absolutely don't think giving out free samples (Sephora style or otherwise) is needed for a successful perfume shop. A lot of sales can be made with an honest and understated but informed and informative approach.