Your herbs need a half day of sun. Look at the sun amount total for the day. I don't know of any herbs that like shade. 5x5 is big enough to grow all the herbs I would need. What are you planning to grow?

I'm not too sure, but I will tell you what I know. I have been growing several herbs in a much cooler climate than yours, in pots on a balcony. This balcony gets only direct morning sun and is indirect sun the rest of the afternoon and evening.

So far, the plants have been just fine. I don't know how comparable that is to your situation, I'm assuming not very. However, it shows that herbs are more resilient than people tend to give them credit for.

If anything, maybe plant some extra of your favorites in a few pots that you can move to a sunnier spot if the rest of them start going south. Herbs take to pots well, just don't over or under water them. Also, make sure you harden them off!! I have made many plants angry by messing up watering and hardening off.

The biggest issue you will get is maybe less vigorous growth, which is also why I said grow a few extra. They say if you can pick between a spot that has good sun or a spot that has good soil, go for the sun. It's easier to ammend soil than light ;) Good luck!