Dont caulk under or flash over the bottom fin, if any water happens to get in, there will be no way for it to escape.

Thank you. I didn't know this.

Your flashing plan sounds like it is state of the art especially allowing the housewrap to be sealed to the sheathing instead of wrapping into the RO. Don't use so much sealant that it oozes out and contaminates surfaces where flashing will be adhered. Be sure that the bottom nailing flange of the window doesn't allow water to roll over the sill and enter the cladding system. Many window manufacturers don't provide enough of a slope/drip under the sill and a "sub-sill" must be added in the field.

Thank you too, mightyanvil. I usually add too much sealant. What is RO and at what point might a "sub-sill" need to be added? Thanks