Even the newest watches have 18 hour battery life, so of course one that is almost a decade old would be the same or worse. It’s actually amazing that it still lasts a whole day after all this time.

Yes. 18 hour battery life has (I think) been the touted range, up until the Ultra came along (excluding low power modes).

Yes, its almost 9 years old

No. It is not normal to charge your device. Unless of course, you intend on using it.