Contractor did some shoddy work installing a water heater last week. Questionable solder, crooked pipes, bent pan, burnt up the wall... (I have seen the owner do good work but he sent one of his crews out)

After closer inspection I found a big dent on the back of the water heater (I didn't pay for scratch and dent) and I am thinking they didnt pull permits to do the work.

I already called the city to find out who the penalties (~$400) would fall on for doing work without a permit and they said "whoever did the work" and it would hit their license if I had a licensed contractor out to do the work.

I want him to cut it all out and I will pull the permits and do it myself. what are my chances of getting him to agree to this?

At a minimum I expect them to replace the PVC with copper that they tore out (drain line for the splash pan), replace the bent pan (they bent the hell out of the new pan they installed), replace the water heater as I didn't pay for scratch and dent, repair the drywall/paint (they burnt it up around the pipe and scorched the paint a few other plces.), replace pipe insulation that was broken away from the pipes and left under the house and replace the cut pipes that were fit up with shark bites with soldered joints like we had planned. I also want all the gas fittings disassembled and verified sealed properly as I don't trust anything his guys did. I also had some new components that were left next to the job that were gone when they left.

Thats not to mention the puddles of solder on the water heater, floor, patio, trash left next to the water heater, rag left under the water heater next to the pilot, cigarette butts and trash in the drive way...

Do I have any chance of getting money knocked off for having to take another day off work?

What should I ask for when he comes out (what should I expect him to repair)? What should I not say? How screwed am I? Where is the line as far as a review online goes, photos, story?

I haven't paid yet, so I figure now is the time to play hardball. I'm hoping if I tell him I will eat the damages to the wall if he takes it loose, not contact the city about the permit issues, and not post a review online then he will walk away and it will be good (not sure if I can legally say this or what I am legally obligated to allow him to repair). But I doubt it will work that way...

Dont be a douche, sounds like his guys screwed up a job for one reason or another, give him a chance to make it right and make you happy. Someday you may need that plummer in the middle of the night and he will say FU!
There is a good chance he is just a hard working guy trying to run a business, good help is hard to find. Be reasonable, give him a chance to make it right. Show him all your complaints(some sound legit) but dont black-male the poor bastard. Good luck.

I will give him a shot, but also give him the option to just walk away.

I wont fry him for what his guys did (I figure its a case of bad help) as long as he makes all of it right, but if he replaces slop with slop I will have a problem. And literally nothing has been done right on this job.

There you go bud, sounds more reasonable. You should get something for your troubles, he will be embarrassed if he is a good man, but to elevate the situation to a pissing contest will leave you both feeling like crap.
If your not satisfied after that then you can drop the hammer, think of a couple extra things he can do to throw in and get himself off the hook, maybe a faucet somewhere add to the house or something. In the end your still the one that has to wright the check and he has to pay those dopes and for the supplies they used.

Yeah, and I know right now I am frustrated and its festering, I'm not frustrated with him, just the work his company did.

So right now I am trying to stay calm and figure out what options I have.

Permit for a water heater is unAmerican.  Who pays a plumber for a water heater?

Lol, no kidding. I just called the power company for a change of service engineering request... one of the questions was, "are you in the city or county?", "County", "ok, no permits or inspections needed, they will be there XYZ date to look over the situation"

I needed a gas line moved to accommodate the change and I am about to sell the house.

I needed it to be done right for resale.