@stampfli You asked so I will give my two cents.

First, you finished an entire pilot. That is commendable no matter how much praise or criticism you receive. You are already 99.99% ahead of most people. This isn't meant to be patronizing, either e.g. I'm not trying to say "A" for effort. Starting and FINISHING something are both skills, so congratulations.

With that said:

1. You're setting is tricky. It's hard to play mental illness for laughs without automatically turning some people off. I'm not saying you shouldn't, but more and more people, viewer or distributor, might say an instant "no" based on it. If it's what you want, just always make sure it's funny, and preferably not at the expense of others otherwise main character might come off as asshole (and maybe he is an asshole, and if so play that up). Also, Takahashi character very off-putting to me.
2. Camera: I'm going to be blunt, it's pretty bad imo. Although the shots of the group setting and later outside scene are WAY over-exposed, and I have some quibbles with your lighting choices, the technical details aren't the most glaring issue to me. It's your, or your DP's framing. Your framing...is not good. The positioning of the characters, the strange negative space...it's just so over the map. Take the scene after the opening where they're checking into the hotel. Old guy who works there: left side of frame, back to main character: left side of the frame, repeat. There is almost no concept of 180 degree rule, montage, etc. Also, almost every shot is some sort of medium/medium close, and you have very little camera movement, so it feels really dull. The characters at times are on wildly different sightlines, some reactions just pop into one another out of nowhere, no flow etc. If I had to offer advice is to really take a look at each set-up, scene, etc. see what you're going for, and what's the best technique to get there. Is the space this scene is in supposed to have a feeling of openness? ?Claustrophobic? Wide-angle? Soft, etc. Btw, some of the scenes ARE classic sitcom shot-reverse-shot, multiple angles, OTS. That's what makes the scenes that aren't more jarring to me.
3. Editing: Has to be quicker, your jokes have to pay off a lot sooner. At times, good, other times way too slow. Plus, it starts really slow, so audiences will get bored quickly.
4. Audio: At times your levels seem right on, other times they don't. Some of the dialogue is very hollow. The music seems to have no pace or related structure to the scenes, and the whole thing is not mixed very well, imo.
5. Acting: Decent enough, seen better, but also seen a LOT worse. Your main character is...okay.

Don't mean to bust your chops, it's still completed which is an AMAZING feat. If you are asking for advice (and I know you're not and won't be offended if you tell me to fuck off), I would take what you have, and cut down to the VERY best things and make a teaser trailer about 2-3 minutes long that's quick and funny. Then go through the episode, see if you can punch it up more and/or what could possibly be reshot.

But if it's done and/or you're done shooting, then throw it out into the world, stand by it proudly, and start working on the next episode or next thing.

I mean this honestly and sincerely: congratulations and the very best of luck to you.