I'm with the others... 1 spare tube and patch kit.

I'd also do one pair of shoes. Even though I had Lake walking clipless shoes, they were comfortable enough to walk in, and so I sent my "comfy" pair home. My next tour I'm going to wear regular shoes and regular pedals. I found a great shoe company that has some half-sport, half-dress shoes which is great. I probably overthink style and looking good, but definitely don't do so at the expense of functionality. These days, there are so many options where you don't have to compromise.

As for tools and such, I'd take what you feel most comfortable taking. Overdo it if you want peace of mind. But I would avoid doubling up on things.

My road snacks amount to a few cliff bars and whatever bread and cheese I buy along the way.

Although I managed with a 1-litre bottle along the Pacific Coast Highway, I was buying drinks along the way as well. I'd say 2.5 litres was my sweet spot. No more... No less and I'm comfy.

As for what else you need for this type of trip, I'd bring a book or magazine. And definitely some Gorilla Tape. Since the tape is large, just unwind some onto a small piece of tube. You don';t need *that* much but it will likely come in handy.

As for shirts, I'm an "unracer", so I don't really wear cycling gear. My first tour I had sports shirts that were anti-bacterial, but my next tour I'll be going the Merino wool T-shirt route, and cotton dress shirt instead of a long sleeve T-Shirt. Just a little extra style. *smile* I do regular shorts and did ExOfficio undies, but looking into Smartwool merino wool undies. Not really necessary for you since you'll be hoteling, but if/when you move to camping, it's worth looking into.