SP Pitching questions

[tzme415]

Need help on some pitching questions for ASA SP no stealing (This was men's but could apply to womens or co-ed too):

Pitcher starts to deliver to plate, but doesn't deliver the ball - like a fake
Is this an illegal pitch, no pitch, or nothing? Does it matter if he steps off the pitcher's plate and comes back to restart?

I am having trouble calling low, below 6 feet, pitches illegal before they reach the plate - any suggestions? If a pitch is illegal and I don't call it fast enough the batter may swing. If I don't say it fast enough can I still call the pitch illegal and is there any recourse if the batter swings because I am late? I don't know why I am having so many problems with this this year.