About how many interviews are done a day at the manila embassy? How many visas are approved? how many denied per day?

I don't think that information is available any longer. Manila used to post a list of all interviews for a month but have since going to specific case inquiry so that list is no longer available. You might try doing some searches at the USCIS website, you might find something there. Good luck

When we were at London there were 16 couples interviewing for the same class of visa that we were, though I can't remember if those 16 were just IR1/CR1 or if that was for all the K-class visas. I know it's not Manila, but I would guess the number of interviews they do would depend on how many they could reasonably process in a single day. London processed less than 10,000 visas last year and if memory serves they only did a few hundred immediate relative visas.

The impression that I got at London (someone please correct me if this is wrong) is that they do immigrant visas in the morning and it looked to me like they were trying to clear them out before 1-2pm. The place was absolutely heaving but it looked like the vast majority of people there were trying to get other types of visas. They had these big screens on the wall with your number on them (they gave you a number as soon as you walked in through the door) and they were divided up by the type of visa you were getting. I saw at least 4 601 numbers up there; I didn't even know what those were until I joined VJ.

This probably hasn't helped at all.