Leaving First Early

[tibear]

Everyone knows about the phantom tag of second base on a force where the F4 or F6 doesn't actually touch the bag and the umpire still calls the out when the ball clearly beats the runner.

Two questions:

1) Generally speaking, how far from the bag do you generally give the defensive person on a play where the runner is say 3 or 4 steps from the bag.

2) Again with the runner 3 or 4 steps from first, do you ever give F3 any leeway when they sometimes step off the bag a fraction of a second before they actually catch the ball? i.e. F3 catches the ball after lifting their foot off the bag.