The thing that I think is most important about Klinger as a character is that he's deeply kind. He couldn't get a section eight because he wasn't willing to commit to making himself a danger to others. His dramatic wardrobe and escape acts never impacted anybody else (other than giving Henry and Potter some extra paperwork on occasion), and he's still a first rate soldier when they need him. He's always in the thick of things carrying litters or donating blood or delivering x-rays. The example I always remember is when he pretended to think he was in Toledo. He wore civilian clothes and talked to Potter as if he were a traffic cop, but he was still doing his job correctly and efficiently. His behavior is a protest more than anything else. It's a statement that he may be acting like a soldier to save lives, but they'll never make him think like a solider; he will do his part to lessen the suffering but he cannot support the war itself.
There's an episode with a guy who actually gets a section eight, and he's so clearly contrasted with Klinger because the other guy isn't just talking to his socks, he's firing into the minefield. Klinger tells Sidney that he hates the war so much because of the death, that he can't stand being a part of all that killing. If he just wanted to go home then he could do it, but that wouldn't actually help anybody. He's a lot like Hawkeye in that way. Sticking around and making it clear how much they hate it while working every day to save lives is the best way to fight "the war against the war" as Hawkeye calls it.
On a less serious note, Klinger is also just a really nice guy. He's even friendly to Frank, who only ever has awful things to say to him. He's surrounded by hate and violence, he's constantly overworked; and yet he shows up, goes above and beyond in his duties as a corpsman and clerk, is genuinely kind to everybody he meets, then spends his free time sewing elaborate outfits and constructing getaway schemes. That's just plain incredible. He never lets his hatred for the war turn him hateful, and instead he makes an effort to brighten up the 4077th with his wackiness.
