Really and still are adverbs. Front, mid or end position or three possiblities?

[Alexandro]

Hi everyone,

Really
- I thought that smoking was my only bad habit, however I eavesdrop a lot and I really can't help it.

- I thought that smoking was my only bad habit, however I eavesdrop a lot and I can't really help it.

- I thought that smoking was my only bad habit, however I eavesdrop a lot and I can't help it really.

Do these sentences have the same meaning? Here are two others with 'really'

- I really can't help you with this. (meaning there's absolutely nothing I can do to help you)

- I can't really help you with this. (does this also mean that there's absolutely nothing you can do to help somebody)

Still

A hotel manager at the opening of his new hotel to one of the waiters carrying a tray with canapes for the guests:

'Provide the guests with new canapes every hour. I don't care if the tray is half-ful still.'

'Provide the guests with fresh canapes every hour. I don't care if the tray is still half-ful.

Do these sentences have the same meaning?

Thanks
Alexandro
_________________
'Everyone can mistakes! After all, nobody's perfect.'

[Beeesneees]

I really can't help it. - there's absolutely nothing I can do
I can't really help it. - I try, and from time to time I might succeed for a short while but it keeps on getting the better of me.
I can't help it really. - You may expect me to be able to help it, but it's harder than I can cope with.

all have slight differences in meaning, but the nuance is very hard to explain. I'm not really happy with what I've said, but I'm at a loss to put into words what the differences are.

I really can't help - there's nothing at all I can do
I can't really help you - I'll do what I can, but I'm not confident in my ability to help.

half full (no hyphen is usual in modern usage, double 'l') - both sentences mean the same.
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Cheers m' dears!

[Alexandro]

Thanks Beeesneees.
_________________
'Everyone can mistakes! After all, nobody's perfect.'