Based on experience, possibly not more then a few months.

That could work but you’re still doing full cycles on the battery all the time. In the end, it might be less then daily use.

A phone is not a UPS.

I’ll say that you probably want .com. Domain names that integrate the TLD are cute, but they can be problematic. Not everyone will pick up on the fact that it’s supposed to be pronounced as one word. This leads into the fact that it can be hard to verbally convey this domain to other people. Very specific TLDs are also likely to have strict or unusual rules on their use that could get them revoked.

Leaving a mobile device plugged in constantly will fry the battery. If you never plan to use it for its intended use again, that might not matter and it could be a good way of recycling and old device. There might be a setting to limit the maximum charge of the battery. If so, limit it to around 80% and that might extend it.