This is quite a long list and some of the expressions are meaningless to me unless I know the context of the words or where you read or heard them. I suggest you limit the number to one or two and give some idea of where they come from.
I have replied under your questions. Could not underline or colour my answers! i hope this helps.
I am seeing water rings again. What is this mean? Why use “water rings” ?
Water rings might be water ripples or the rings seen after one throws a stone into a lake? Or water rings as in stains???
Giving us the context will help resolve this one properly.
I do it for their own good. What is “For their own good” mean?
It means that the character speaking is doing something for the benefit of someone else.
Caregiver. I think it means babysitter. Am I right?
Carer (UK, NZ, Australian usage) and caregiver (US, Canadian usage) are words normally used to refer to unpaid relatives or friends who support people with disabilities.