Mother earth news put out a book several years ago about what types of plants do well together and which ones are good for pest control, both creepy crawly and four legged types. Sorry but there is no way to really stop the chickens short of the frying pan, the fence will work for a little while but my grandmothers chickens would dig under the fence.
If you use drip irrigation make sure you put plans together that like the same amounts of water, corn will not do well if you water it as much as melons.
Support your tomatoes like you would the pole beans in addition to the pails.
Cucumbers planted around the melons will produce sweet cucumbers.
A good time to add chemicals is when till under with this year’s garden. I found this good for my plot but it will cause plants coming up in random places next year.
Hot peppers are good pest deterrent to some pest but I have seen dogs harvesting them up to and including habaneros. good luck and happy gardening.