On the fourth watch, wow; Zephyr is just... absolutely pathetic and pitiful.
He's almost like a male Trixie. He has a huge ego, and he doesn't have a real home of his own and is in many aspects a complete failure. However, where Trixie has drive and believes in her talent, Zephyr has no self-esteem.
On the outside, he's completely different from Fluttershy in terms of personality, but inside he also suffers from a lack of self-confidence. Although, Fluttershy has definitely overcome that hurdle over the seasons.
I won't argue against Zephyr being a tool, he was manipulative and lazy; but at the same you can see why he is that way. I have a feeling he was extremely coddled growing up, which is why he's so dependent on family to get anything done, and even then he doesn't do much to improve himself. He has absolutely no motivation.
But when he finally succeed in mane therapy, as obnoxious as he had been, that's when something really stood out to me that I believe rings true for most people: you can try all you want to do a good job and succeed, but if it's something that you have no interest in and were put into than rather seek it out on your own, you'll never do it exactly right.
It was obviously overexaggerated how much he failed each job, but it doesn't detract from it: he had a real drive for mane therapy, but his lack of self-confidence prevented him from sticking to it. But after getting some encouragement from his sister, he went into it with both his passion for mane therapy as well as a belief in himself that he could do it, two things he never had at once. And he's obviously very talented once you can get him out of his funk!
In that regard I can relate, though in a slightly different way. Give me an assignment where I have to analyze a poem, and I can give it my best. I can probably do it without a hitch, but it won't be as well done with visible passion as an assignment as something I love. I don't know how to explain it, there's just that "mmph" you can detect in something when it's done by someone passionate about it.
Think of cooking; if you're just someone cooking because you have to, there will obviously be something lacking in the dish. But if you're passionate about cooking and you love it, it will definitely show in quality of the meal. I can't tell you how many times I've eaten something by someone who was not only talented in their craft, but loved it as well. It really makes all the difference!
I think I'm kinda rambling at this point, but I hope I didn't jumble things too much. Long story short; while I don't condone Zephyr's actions, I can see what caused him to become who he was and do the things he did. And I really enjoyed Fluttershy being a caring, responsible older sibling and helping him see his self-worth. It's obvious that mane therapy is his talent, and that with this new reassurance he can probably be really successful in it! It's hard to evaluate him based on one episode, but I'm sure as he becomes more and more successful and happy with his job, the less of a tool he'll be and the more of Zephyr will shine through. I would definitely like an episode in the future to catch up on him and see how he's fared.