Does a UPS still protect my system with backup power when it's plugged into an ungrounded outlet?

You do not. In the US you can do basically all your own repair work on anything in your house in most jurisdictions. There are some municipalities and HOAs which cuck people out of doing their own work, but the majority do not.
If you fuck up, you're liable for any injury or damage. That's all.

In my county I was able to do all my own electrical work, but I had to get a certified electrician to come out and certify everything I did (I changed out mains power and the electrical panel and then redid most of the wiring in the house)

Upgraded from 100A mains power to 200A.

Please fucking pay someone to do it

no it’s just bonding the plate not grounding it

I'm going to upgrade my panel to a 200 or 250 Amp service since most of my breakers are taken. Every room in the house has two 15A breakers for some reason. I'm just going to pay an electrician to do it for me because they'll label everything and the panel is a bit of a mess.

I put a new room in my basement, wires up the outlets to a new circuit and installed lighting on an existing circuiT, did all the framing and drywalling myself . Never called a trade once. Never got an inspection, all is well

Yea that's basically what I had to do, removed the entire previous panel, re-did a ton of 15A circuits with 20A, then added a 40A circuit to my basement workroom.

I'll be trying to sell in the next 10-20 years, so I didn't want to have to deal with questions when that process starts, so I paid like $750 for an electrician to come out and spend like 6 hours going over all of my work and certify it.

Hi I have a custom solar off grid setup. Here's what you need to do. You need 3 prong outlets, you need 3 wire wires, yes it's an expense, you need to wire everything properly and polarity matters. Then you drive a long 12 foot spike into the ground with like 4 inches showing, and you run your ground wire to that. Stop being a lazy piece of shit or you're going to burn your house down.

Yes, the UPS will still power the system.

That sounds like permit work, which usually requires an inspection. Even if you had a licensed electrician do the work they still need final inspections on most permit work.

Upgrading the service is a great way to ask $10k more when you go to sell the house especially now that EVs are becoming more popular.
I'm probably going to put a NEMA 6-50 in my garage. Luckily the run would only be about 5 feet from my panel box so it'll be cheap to install once I upgrade the service.

You technically aren't allowed to call it a bedroom in the basement or add it to the square footage of the house unless there's an emergency escape window. My sisters house is listed as bigger than mine despite mine being much larger because her basement has the escape window and counts toward the square footage and mine does not.

>tfw used to have ground recently found out I no longer do
Explains why I'd get the tinglies when I touched my metal server chassis and space heater at the same time