The unlawful presence starts from i94 expiry. So, yes, you should count days starting i94 expiry.
You can go anywhere out of US to get H4 visa stamp.
NPT is ‘nunc pro tunc’ which is an option to file H4 Extension after i94 expiry and request USCIS to give approval from back date. This varies by your situation.
In your case, it is difficult as you have already spent more than 180 days.
The automatic ban can be waived off based on your situation.
See these recent cases: