The claim that drinking tobacco is 'an integral and very important part of an ayahuasca ceremony' may be true in the ceremnoy you participated in but it isn't true of the wider ayahuasca drinking communty in the Amazon and all over the world. So far I am not aware of any deaths from people drinking ayahuasca with only caapi vine and p. viridis leaves, however there are a number of confirmed deaths from drinking tobacco.
With respect to you, and with appreciation for you sharing your experiences, I feel it's important to let people know that there is risk here.
My personal opinion is that just as indigenous people are often more susceptible to diabetes from ingesting sugar, as they have not genetically evolved the same tolerance westerners have - some westerners may be particularly vulnerable to drinking tobacco. I suspect that a small number of the population can have an allergic reaction and potentially die.
There are many medications used in allopathic medicine which have a similar level of risk. There are certainly benefits to drinking tobacco or taking medications if they are needed and served responsibly. The difference is that when drinking tobacco, the person is not near a bunch of machines that can keep you alive if you turn out to have an allergic reaction that could be fatal.
http://www.stuff.co.nz/national/71864946/kiwi-matthew-dawsonclarke-dies-in-peru-after-tobacco-purge
RE: Shamanism, tobacco & ayahuasca: what to expect and how to prepare.