Fox gloves (though maybe avoid if you have young children, or animals who are likely to eat them).
Lupins
Linaria purpurea (not native but naturalised basically everywhere in England), the bees and other pollinators absolutely love them.
Lobelia of different varieties.
Elderberry is a nice option, flowers and berries can be used in recipes
Apple, plum, pear and peach are all good to espalier
Gooseberry and currents will grow no matter what.
Budliah is great for bees and butterflies, is very fast growing and has lots of flowers for basically 9 months of the year. I would be careful with he variety you get, make sure it is a dwarf variety as it likes to self seed and the larger varieties can require multiple trims a year.
Use things like rosemary if you want relatively short boundary bushes, can also be used for cooking, they like being pruned back etc