When is it time to stop calculating RISKS and REWARDS, and just do it?
Never in one sense, soon in another.
It seems to me that all of life is a calculation of risk and reward, and most of it is done subconsciously, moment by moment.
And often there is little to be gained from extended conscious review – most often the most powerful outcomes are created from just going with the subconscious flow (and sometimes the signals of risk from the subconscious are subtle – it pays to be alert to them).
Agree with almost all you said.
The one exception is the “to try” one – Not only does not trying ensure failure, but it also makes you a stationary target for anything out to get you. Often the safest strategy in a dangerous environment is to keep moving, as unpredictably as possible. So in that sense, the overall risk is substantially reduced by taking small (intuitively calculated) risks into the unknown as frequently as possible. And most of the predators around today come armed with rule books of one form or another, or armed with deceptive advertising strategies designed to extract any surplus you might have gathered, rather than teeth or claws (and most religions fall into one or both categories as far as I am concerned).