I wouldn't call testing "training wheels", and I wouldn't compare it to brain rot from using a calculator. Test code makes you think more, in fact.

As for the rest of the stuff, you have to find how you work best, adn do that. Don't necessarily try to copy how someone else works.

For me, I try to create small, compartmentalized code that I can easily test. With small bits, I don't need a big block of time to work on it (more breaks without losing context), can write focussed tests, and can make easier changes. A long hacking session isn't necessarily bad, but if you have to do that to get anything done, you aren't being effective.