Re: Are Foot Faults necessary, your call?
No. From experience playing tennis, it doesn't make a difference unless it's a huge margin (like on half of it). Touching the line even slightly isn't going to give you an advantage, most of the time you don't even think about it anyway. At least in my case, I don't think being a hair on the line is going to make a difference whether I hit an ace or a double fault.
Kind of off-topic, I believe a foot-fault should just be a 'let' do the serve over. It's not worth losing a point serve over, let the rallies do that for you.
Serena "Making Threats" Williams
Venus "Always Injured" Williams