Zam zam

Q: Can zam zam water be drunk with meals? Does one have to stand when drinking zam zam water?

Q: Do we have to drink zam zam water standing up facing qibla?

Q:

1. I have witnessed many Muslims standing up when they drink Zam Zam Water. Those who sit and drink are being ridiculed by many people and even Mullahs who justify that we must always stand up while drinking Zam Zam Water. 
2. I have also witnessed many people standing/walking while drinking water and eating dates in Haram Sharief in Makkah. But, the Sunnah of Rasul Allah Sallallaahu Alaihiwa Sallam is that we must always sit while drinking or eating. Please clarify in detail.