One way to know if a site is relatively warm (has a longer growing season with fewer killing frosts) is to look for land in mid-fall when you can compare how far along native trees are towards dormancy. Best fruit growing areas are often known in the East and will already have established orchards. People have been growing fruit here for 300 years but you might luck out, I guess, and discover your own tiny "banana belt". As far as productivity- of course you will be able to grow a wider range of varieties in a 6 than a 5 and some would yield more with a longer season- at least over time. But your question really seems to be can you find a Z6 in regions that are predominantly 5. I think it's the leeward (southeast) side of large bodies of water that have moderated temps as in far upstate NY, not far from Buffalo and areas like Lake Geneva. Also along rivers such as the Hudson Valley and running up the Housatonic in CT. Some of the fruit you listed, like cold-hardy figs and Jap persimmons aren't going to work for you, even in a Z6 without protection.

I can only tell you that one appeared as a volunteer in my vegetable garden this past spring. At first it looked like a tomato plant but it grew so fast that I knew it wasn't within a few days. I had no idea so I posted it on one of the please ID forums and was quickly told it was hops, and unless I planned to micro-brew I should get rid of it quickly or it would take over everything and be impossible to remove completely because of runners. I pulled it out and seemed to have gotten it all. My DDIL in RI later told me she planted "the pretty vine" and it grew everywhere and choked out lots of her plants. She had a really hard time getting rid of all of it. So... my only warning is to make sure that you really want to grow it, and I don't think you'd want it in the middle of one of your flower beds.

flora's comment is spot on - I guess I kind of thought that went without saying, but I'm glad she said it! You definitely want to plan each side of the sidewalk as one cohesive garden. One other thing that I keep coming back to. I know I said that if it were me, I wouldn't go too high with any plantings because I would not want to hide the beautiful stonework and porch. That being said, you do want to try to have some varying heights of plants, and I even wonder if I would put something off to the far left (as you look at the house). Ideally, I see a small tree there, but in my entire gardening experience I have never seen a small tree that stays a small tree. And by small I mean like 10 feet, lol. I wish someone would breed something that would stay that height. Anyway, maybe something like a pyramidal conifer of some kind forward and to the left of the left end of the house. Again, not sure of sun conditions and what would work. Or maybe a low-growing, mounding japanese maple in that spot. It wouldn't grow that high but would certainly be a nice eye-catching addition (again if they grow in your sun conditions. I have no experience with japanese maples but love them, lol! Haven't had the courage to decide on one and plant it yet!) Anything taller in this spot would (I think) help balance things and add variety in height at the same time, and also extend the bed which IMO isn't a bad thing. I just think you need to find some kind of balance between hiding your lovely house and ending up with a garden that is all at the same level. I don't know, maybe even some small, pyramidal potted evergreens on the insides of the inner columns... or maybe a clematis growing up one of the columns... or even hanging baskets in summer...

Toni Those are spray-painted succulents (not cacti) - you can see that new growth (center of the rosettes) is already different color, green as they should be. The spray paint may start rubbing/peeling off so if that happens don't be alarmed. During that time they may not look that attractive, but hopefully will grow out of the 'fake colors' fast. They are probably echeverias. All succulents need good drainage - containers with drainage holes, and well-draining 'soil'. They don't like sitting in wet soil. Lots of light is important, otherwise they will stretch looking for light.