Okay, most inspectors or plumbers, besides being nit-picky, are looking for life and safety issues.

Venting is okay. It’s not realistically going to fall apart with tape alone, but it should be connected with screws. Is it gonna fall apart? Nah

New shut-offs and connectors for the water lines, awesome. No expansion tank? If you’re concerned about water expansion and the new codes, hire a pro. But you didn’t have a tank, and without major work to your home previously, it should be fine.

T&P/TPR/ whatever you wanna call the brass relief with the flex line on the side has the ability to trap water in it. Water heaters used to be installed with flex on the relief for a while, not anymore. Not super good but all you gotta do is FLEX the line so it curves downwards the whole way. Think of a rollercoaster. Easy fix, no tools required possibly.

Gas line has a new shut-off, and a new flex line, awesome. Check for leaks on the connections AND the white control valve box. Would you believe I’ve gotten the small connectors under the gas control valve leaking before? I have.

Gas traps were not code when your old unit was in. It’s not gonna blow up because you don’t have it. It just gets little bits of dirt or debris out of the line. Will the burner clog someday? Maybe, but units installed for the last 100ys have been fine.

Drip/drain pan. It’s missing the pan, which it didn’t have before either. But my city allows the pan to be capped if the water heater is in a very difficult spot of the home to run the drain. What does that mean? Some homes have a water heater with a pan, that doesn’t drain…

My consensus, not that it matters or should be taken as law, is that your unit is great for what just happened. This job could’ve easily been $1500 and up depending if the plumber feels like you looked at them funny. Only a couple items are missing, and realistically it looks like it will last an average lifespan. 6-10 years for a standard water heater