You've actually just highlighted the two main concerns I have with this which may lead to premature failure.
100degC+ environment - did you post cure the tank to higher than this? most off the shelf epoxies have a Tg around or lower than this so you'll loose a lot of strength as the temp rises, even if the epoxy has a Tg higher than this do you really want this component post curing in service? I certainly wouldn't.
vibration - the threaded connections where you've tapped directly into the laminate - a) as already pulled to note by others, this is not an ideal way to fix the sensors/inlets/outlets etc b) I've used/got similar sensors as the ones in your picture so I know they are relatively heavy, shake those suckers around in the back of a car for a while and something is going to give.
I've built a number of cars over the last 20 years and I can pretty much guarantee that although it may work on the bench or for a while on the car, something will give and you can be certain it will happen when you least expect if or really don't want it to happen. The underhood/clam of a car on the road and even worse on the track is a very nasty place and will cause failure of any component not 100% up to the job. The best case senario at failure is a small leak and loss of pressure causing you to limp back to the pits or pull over, the worst case I wouldn't want to imagine the fallout but I know from cars I've worked on, a clam shell does not really offer much protection from a failure from inside the engine bay.
If you want to see what can happen when a pressure chamber fails at temperature, take a look at the mythbusters heater clips
https://youtu.be/jbreKn4PoAc?t=2m34sdifferent materials but you get the general idea.