Visitor visa extension question?

[star12]

Hi,
I had some questions about visa extension.
1. I read from various posts that it takes 5 months or so to get extension. So if intial 6 months is over and still you dont get the result of extension application what happens, should the person leave the country as per I-94.
2. What if extension is denied, should you leave immediately or can stay the initial 6 months which was given on I94?
3. Does extension of denial affect the 10 year multiple entry ?
Anyone who knows please share views.
Thanks

[immihelp]

1. You can stay up to 120 days after applying, even if it is past original I-94 date.

2. You can stay until I-94 if still not expired. Otherwise, leave immediately.

3. Yes, they are considered invalid.