There is especially one Thing I've learned through your comments: This seems to be a common problem! And this calms me down a bit.

So, I will get a much bigger battery. That's easy! :-)

Later I will go for a heat-shield for the starter. Is there something in the market or do I have to make my own?

The carb has a vacuum and the tube is going from the inlet manifold to the back of the carb. The distrubutor is about 4 years old, but hardly used. I do not know the make, because I did not change it. I replaced the coil about 3 years ago.

I will make pictures of the carb from above in Cold and warm condition, but cannot do it today.

Now my question is: Did all your tight-engine-problems go away by time through driving the car? Will it get loose? Or will it stay like this?