Nice house! I like both the porch and the overall proportions and design. I'm afraid I agree with the suggestions to remove the plants that are too big for where they are and shift the arbovitaes away from the foundation. I try to plant woody plants to accomodate their eventual size and then put in annuals, vines and perennials to fill the space while they grow. Consider foliage color and texture while you are thinking about your new plantings. An all green bed can be restful, but will be of more interest if the foliage texture is varied. Many of my spring blooming plants are situated so that their foliage size and texture contrasts with that of near-by plants: iris with Veronica 'Georgia Blue', Baptisia, and Hydrangea for instance. For foliage color, there are plants with cream or yellow variegated foliage such as some of the dogwood (Cornus) shrubs and small trees or wegeilas. Some wegeilas have dark red foliage as do some of the ninebarks. I also try to have at least something blooming most of the growing season. Two of my favorite summer blooming plants are the later blooming clematis and hydrangeas, either the H. paniculatas like 'Limelight' and 'PInky Winky' or H. arborescens like 'Annabelle' or the reblooming and hardier forms of H. macrophylla like 'Endless Summer', 'Penny Mac' or 'All Summer Beauty'. Both the hard prune (type 3 or type C) clematis that bloom in summer and the summer blooming hydrangeas bloom for at least several weeks for me. I grow some of my clematis on stuctures like obelisks, but others I grow through shrubs and small trees that have finished blooming earlier in the year such as Cornus alternifolia, and the clematis provides an apparent second bloom for these plants.

I assume by modern you mean more up to date. Not necessarily modern style like sharp corners, colder tones.... I love what you did and I think adding black trim would be amazing. Remove the landscape. You don’t need much by the porch. You need some by the right side of the house and for that I’d do something neat and simple. Two rows of boxwoods? I would for sure update the walkway. Maybe the same whitewash brick in a herringbone pattern. And can’t wait to see the new shutters. This is such an awesome home!! Love it. Love what you did. Looks amazing and will look even better!!

"undulating shrub tube". haha, best description ever. maybe it's not in your plans, but I would consider painting the stucco and brick too. the red bricks with red roof and tan siding is kind of 70s looking to me (sorry!). you might even be able to stucco over the bricks for a more consistent look (IDK, ask an expert). I'm so happy you're considering environmentally responsible landscaping options! go to local nurseries which will help you find the right kinds of plants. native plants will be the lowest maintenance and happiest in your particular zone, and they benefit birds as well! (edited because I just realized you said northern california.)

I agree that this is a landscaping issue, but would also suggest that the railing around the porch roof is not a positive feature, especially since it is obvious there is no access through that window. I would remove the railing detail. I would also remove the shutters from the double window upstairs on the right. Pop your front door with brass hardware and a brass kickplate. I don't see any lights on your porch. Can you remedy that? Replace the tan urns with larger ones in black or charcoal that stand on a foot like shown above but much larger. Fill with a bonsai twist evergreen covered with some tiny battery operated lights. For the season, surround the base of the urns with low pots of red poinsettias. IMO, your white trim is just a bit too bright and contrasting, but you can always change that next time you paint.