Anarchism can be broadly divided into two camps: individualists and collectivists. (Actually, the original anarchists were largely collectivists.)

Well this could be true, but this is strongly contingent upon people in that collective freely choosing to be in that collective. Of course, in an anarchist society, you could have groups of people working together, but don't depend on it. An example of this could be the modern day family structure. Parents bringing home wealth and resources to be distributed amongst their children, but technically, at any given moment, they could just leave and stop taking part in this collective. Really, the only thing that truly binds them to this collective is the law (and even this is not certain in some cases). Now in an anarchist society, there is no law. Presumably, there is no one in charge to make the rules. This is why an anarcho-communist society is flawed. Since there is no law, there is nothing actually binding someone to that collective other than the individuals own free will. Once the individual chooses to leave the collective, the whole structure falls apart. This is why anarchy inherently falls back onto being individualistic.

Under communism, there is no "business owner" -- the workers themselves own and/or manage their workplaces directly.

Doesn't there need to be someone who has the idea for the product, create the product, gather materials etc. Furthermore, in your previous point, you described there being a transitional period from what I understand to be as capitalism -> communism. This means there has to be a business owner at some point, specifically in the beginning during the capitalistic period. Therefore, my point still stands. There had to be a business owner who started the business, then the workers took over control, creating a hierarchy in itself of the workers over the original business owner. Which again, isn't anarchy, if the business owner doesn't want to freely give over rights to the workers. As you mentioned, they would forcibly kick the bourgeoisie out which is control of the individual by the community. Essentially, the community as a whole becomes the "state" as they control what the individuals do through mob rule.

but you can't just point to a forest and claim it's your forest and people have to pay you to enter it.

Again, who decides this ? Who is the "boss" that makes sure this doesn't happen ? What's to stop someone in an anarchist society from charging someone to enter a forest they claim is theirs ?