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 :-)

Clematis for part shade... please see link. I have a marvelous arbor (custom built, redwood) with a bench underneath. While I agree that it stands very well on its own, I won't be sitting there much until I get a vine to cover it so I can have some more shade. :) Be sure to check on the ultimate height of your chosen clematis; this can vary a lot. Check laspilitas.com and see if you can get a CA native! Some are loved by hummingbirds. Here is a link that might be useful: part shade clematis

Grindelia squarosa? When seeking i.d.s for anything in Asteraceae, a pic of the underside of the flower is extremely important, and sometimes essential for an accurate i.d. .https://www.minnesotawildflowers.info/

Thanks 1stK, Chris and Jandey. My seedlings are coming into their own and providing a true source of delight. Next up, another of my Mango Blush seedlings popped it's two first flowers...smaller flower, heavy texture, knockout fragrance. Fun stuff!