thoughts on my build

I think the comp. ratio is a tad high. But hey, if it measures out and specs up at that......Pump gas would be a concern. I'd rather run a tad under on the ratio than have to much and have to retard the timing in order to make it run without pinging.
You lose more power from retarded timing than low comp. ratio.
Cometic gaskets, though expensive, can provided a thicker gasket to drop the ratio a tad in the exact bore size you need.

The carb is a give and take. Though I'm with a vaccum secondary carb for auto on a mild build, if you can run the DP and set it up right, you'll enjoy it more than a VC Carb.
Also the total HP output of the carbs CFM difference isn't that much.
You'll enjoy the smaller carbs streetablity over the larger one.
The higher velocity through the carb offers better throttle response and potential gas mileage.

IMO, I think it's a good build.