Clicking/Ticking BEHIND Gas Stove

Get the 220v outlet while you can. With that wiring, you can run two 110v circuits in the future or install an electric oven if you change your mind. Running another line in the future would be much more difficult, so now is the time to have it installed. The only change you'll likely have to make is replacing the double breaker with two single breakers if you want 110v, which any electrician should be able to do with minimal effort.

The click-click-click sound is probably coming from the water meter.

Check if it makes the same sound when you run COLD water, in a kitchen sink, for example.

Sometimes a mixing valve is used to put some hot and some cold water into the toilet tank to prevent or limit the tank sweating in the summertime. The mixing valve is adjusted to "temper" the water by adding just enough hot water to raise the temperature of the water in the tank from cold, to I'd say "lukewarm", but not hot. The water is then much closer to room temperature, so it won't "feel" hot, or even particularly warm. If a mixing valve is installed and the water feels hot or even particularly warm, or even on the cold side, the valve needs to be adjusted.

In either case, cold water only, or a mixture of hot and cold, some water meters just "click" as they measure the amount of water flowing through it.