My opinion is that it will be tough to make two identical planters look the same with a significant difference in light. As you discovered last year, you will have one grow well and one less well, and which is better depends on what you planted. You can easily keep it similar (like red petunias in one vs. red impatiens in another) or if it were me, I'd mix up one or two same plants with different accent/thriller plants as the central focus. For example, Bacopa grows nicely in either situation (still wont be identical though). With white blooms that cascade over, the idea would be to present the same color SCHEME (taller purples; shorter yellows, or what have you) vs. the exact same layout/plant. The eye would catch a flurry of your choice of colors on this side and the other -- without zooming into a noticeable size and quality difference of two identical plants where one is visibly thriving over to other. Just my thoughts!

Any broadleaf evergreen will produce flowers. Even though they might be tiny and you not notice them, the bees will :-) Conifers do not produce flowers as most of us recognize them so no nectar production that would attract bees and they are pollinated by wind, seldom insects. If you don't want any bees, go with a conifer. FWIW, the flowering period of most broadleaf evergreen shrubs is relatively short, so the bees don't hang around long - when the flowers are over, they move on. And when they are present they are busy - they won't bother you unless you bother them. Boxwood is a very common, almost ubiquitous, hedging plant and is used in similar situations with great frequency. And it is appealing to bees when in bloom but that does not discourage its use for this purpose by 1000's of homeowners. You may be being a bit overcautious :-)

Sounds like slugs. A slug bait containing iron phosphorus, beer traps emptied frequently, hand picking and squishing are some control options.

Clematis with no doubt, just make sure You get a plant that's at least 2 yrs, it is still gonna take a couple of years to perform it's best but at least you see blooms meanwhile. I can't post names of nurseries, spike won't let me, but look for hallsons in michigan.. klk