Pls Advice

Yes, fot hygiene purpose. Its cleaner.

Yes, because sometime after pee, even we wipe off, it’ll still have 1-2 drops. And have discharge too. And it’ll be good if you can change after lunch, if you start working in morning, as it’s help to air and keep it away from being smelly. And it’s easier to wash undies from the stain also. Unless you don’t have this issue.

Yes but replace regularly

No

Yes i’ve been doing that for years, however when I sleep, i dont wear pantyliners except when I noticed discharge is more than usual

Yes. That's what I have been doing for many years.