3-day notice to pay rent or quit

1. No--the notice must be mailed in addition to being nailed.
2. No--can only ask for rent in a 3 day notice to pay rent or quit. Late fees and interest are not rent. It is not usually legal to charge late fees in residential rental agreements.
3. No--the lease is terminated if you leave within the 3 days.
4. Yes, except for the amount of rent that is due per the notice.