A CA cigar B&M shop that is restricted from allowing smoking within its establishment? That's a toughie. It appears comfort and convenience are outta the picture and you're limited to competing by price and selection - two considerations that seem at odds with each other with your lease and tax costs.
The only thing I can think of, and this is reaching deep for any possible solution, is for you to offer free coffee to your customers. Something to encourage them to stay a bit and continue with their window shopping of your products. The longer you have eyeballs staring at your merchandise, the more sales you'll pull in. I would think you'd also increase your sales of less popular cigars. I mean, if I spent several minutes staring at a merchant's entire facing lineup, I think I'd probably talk myself into trying cigars I've never really paid attention to just for the heck of it. To continue this line of thinking, and to reach even deeper, I'd consider serving that coffee in very inexpensive small'ish sized coffee mugs. Or I'd think many people would likely say, "thank you", and quickly walk out with that disposable cup of free coffee and provide little benefit to your business goals. Use vacuum sealed thermos dispensers to keep the coffee hot without burning on some warming plate.
I feel for your business. When I seriously entered this hobby, I always daydreamed of owning "the perfect B&M". I'd rather drink battery acid now. Horrible market environment now.