I don't understand how B-cells work. Is this right?

[Kemosabe]

I've watched a decent number of videos and done a fair amount of digging, but haven't found a satisfactory explanation. The bolded part is the part I'm the least sure about:
So from what I understand inactive B-cells are MHC 2 antigen-presenting cells meaning similar to other MHC 2 antigen presenting cells they would have to phagocytize an invader/pathogen and present a protein of it on its cell surface. After they do this they are inactive until a helper t-cell comes along with its cd+4 receptor and activates them causing them to divide into plasma b-cells and memory b-cells. Plasma b-cells release antibodies which target the microbes with the specific antigens making them easier to be targeted by other immune system cells. Memory b-cells stay in blood and lymph fluid inactive until the invader returns and when the invader returns they don't need to be activated by helper t-cells to proliferate. This is why secondary immune responses are so rapid.

Is this accurate? The bolded part is what I'm the least sure about, as I've read sources that say b-cells stay in lymph and just release antibodies, so if that is the case, I'm thinking that an antigen would somehow bind to the b-cell and then it would be activated. Which is right though?

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[Ulgarmoose]

My understanding is that MHC 2 antigen-presenting cells do have to phagocytize antigens to present a protein on the cell surface

B-cells appear to have the ability to be MHC 2 antigen-presenting. Logically then, they must phagocytize antigens. I've read that B-cells are able to directly interact with antigens in the blood, so this must be the interaction referenced (in contrast to helper T cells which do require that MHC antigen presentation and do not directly interact with antigens).

I'm thinking that B-cells are more involved in the response to signaling by T-helper cells than in starting that signaling, although they're capable of both. As if they will phagocytize and present a protein if they run into an antigen, but it is not their primary function.