It can be somewhat tricky to assign a moniker like 'adrenalin junkie' to any character in a Disney show. This is mostly due to writing and storytelling techniques.
One thing most, if not all, Disney series have in common is that the main protagonists (and quite often the main support characters) closely fit the 'adventurer' character archetype. Many series will require the main cast to travel frequently and become entangled in the most impossible situations that most people would find very stressfull or at least too dangerous to see through to the end. However, the story demands that they are heroes, and a hero that does not like adventure in one form or another makes for very poor viewing, unless it's played for comedy's sake.
When it comes to stunts, Kit is one of those characters that have to show, time and again, that they are not as they seem. As some viewers might not be familiar with the series or his character in particular, those stunts are a way to show that he is an adventurer (marking him as one of the heroes of the series) and that he possesses fortitude and stamina above what might be reasonably expected, thereby validating anything he might be required to do during the course of the adventure.
Baloo is very much the same way, his aerobatic stunts a showcase for his flying skills and to enshrine him as the undisputed hero for the series.
Either of them doing this in real life would mark them out as adrenaline seekers, and both would likely hold a job as stuntmen quite easily. In reality, however, individuals like this who seek thrills and /have the skill to pull them off/ are thinly sown. In adventure series, cartoons especially, it's a job requirement
