Food and water in the Midbar - Updated

In parshas בשלח Hashem provides food and water for the Jewish people in the Midbar. Here are a few questions related to that:

1. Manna was provided for the people.  What did the animals eat? The Torah states that each person got the amount of Man needed to feed the people in their household. This would seem to exclude the animals. Yet, we know that the Jewish people left Egypt with extensive livestock and they had to eat something.
2. The Torah has a list of Korbanos (that were brough in the Mishkan) that require oil and flour (or loaves of bread) and wine (Mincha, Todah, etc.) . Where did the oil, flour and wine come from?  They could not have stored enough oil and flour and wine for 40 years in the desert when they left Egypt. In any case it would spoil. Additionally, on Pesach people needed to eat matzah to fulfill the mitzva, where did they get the flour from to bake Matzah?
3. Water was provided by a rock. However, for a rock to produce enough water for 2.5 million people is simply not practical. People need at least 40 liters per person a day, that means 100 million litres a day flowing from a rock. For people to actually collect that much water per day would mean that this is what they did all day and nothing else. Can you imagine 2.5 million people queuing up to get water every day? This also leaves out the water needs of all of the livestock that they had. Did the livestock drink from the same source? How would that work?

In short, even with the miraculous Man and water from a rock, it is not possible that 2.5 million people would have had enough water or other food supplies.

Update 4/6

Tosafos in Menachos 45b discusses the issue of flour. Rashi in fact states that they had no flour in the midbar and therefore did not make the שתי הלחם. Tosafos disagrees based on a Gemara in Yoma 75b that they bought food from merchants in the midbar. Therefore Tosafos says they must have bought flour as well.

In truth, the Gemara in Yoma that they bought food from merchants seems quite bizarre. There is not even a hint in the text about this. Also, what merchants are there wandering in the desert to sell food to the Jewish people? One of the big questions about the whole midbar experience is where is the archaeological evidence. The answer I have always heard is that the Jewish people lived on Nissim (man etc.) which didn't leave any trace. However, if we accept this Gemara in Yoma suddenly everything changes. They bought food and other things from merchants. If so where is the evidence?