What’s the difference between them?

“Reflect” is to consider or realize, so reflecting and thinking are very similar. “Made me” and “kept me” are obviously different: “made me reflect” is like “forced me to think” while “kept me thinking” is like “had me thinking over time.” “All about” and “above all” are not the same at all. “All about” is everything related to something (“tell me all about your vacation!”), and “above all” refers to the most important thing (“above all, take care of your health”). “Tremendous” can be used for negative or positive things, while incredible/amazing/awesome are used mostly for positive things nowadays. For example, a tornado might make a “tremendous roar.” You could probably use these all interchangeably.

They're quite different, really. "It made me reflect" = something caused me to reconsider my opinion. "It kept me thinking" = something caused me to think about it more. "All about" can mean many things in different sentences. Usually, it means something is comprehensive; all-encompassing. "Above all" usually indicates the most important aspect. Tremendous/incredible/amazing/awesome are largely synonymous, and often interchangable. We have a *lot* of superlatives, and their exact use varies amongst different speakers.

All about ≠ above all. These are quite different. All about - is likely describing the topics covered by something. That book is all about science. The book - from start to finish - is about science. Above all - is often used to emphasize something. It's the most important thing. Above all, I just need some water. In this case, he's thirsty. He might also be lonely or hungry. But "above all" he just wants a drink.