If you are growing lettuce in the summer months, I would suggest shading them from full sun with a lattice leaning over them or some kind of latticed tent. Otherwise, they can bolt.

Definitely keep the mints and oregano in pots since they like to spread from root runners.

If you don't like plastic pots, I would suggest glazed terra cotta or glazed clay pots. The glaze will help retain the moisture. Otherwise, the moisture gets pulled into the pot walls and is released to the outside air. Wood is hard to keep moist for the same reason, and will eventually rot out. If you are building wooden planters, be careful when buying wood-- do not get pressure treated. Sure, it will last long, but it will leach chemicals into your soil and then into your food's roots. I would go for sustainably grown and gathered redwood.