This page tends to be an "add as you go" page that answers questions that beginners and intermediates may ask about particular elements in the language that confuses them or they find to be "void." Such as the lack of gramatic gender.
Different languages have different concepts of gender. In Lojban, the closest thing to it is the textual gender used to assign lerfu variables to referents. See lerfu pro-sumti, and why ko'a sucks for more information on some Lojbanic ways to deal with anaphora.
This requires actually understanding the meaning of the words. In Japanese, contrary to popular belief, the words do not imply the gender of the speaker. Rather, they reflect the speaker's attitude and politeness about and towards the environment around him, and his perceived status in it. Combinations of le'o, ga'i and others suffice in this case.
In the case of actual gender, there is no attitudinal. However, consider, is the speaker actually making a point of the gender? Or are they simply following the rules of the language, in the most expedient fashion possible? We suggest you do the same (in either case: if the speaker needs to state something about someone's gender, then by all means do so explicitly. You can use words like {nakni} and {fetsi} and add incidental information with {noi} clauses, perhaps).
(Related to the previous question but not entirely.)
No. mibrirni is a lujvo and, whatever it means, it functions like any other brivla, so {le mibrirni} is a sumti that refers to that which I describe as a mibrirni (a "me-parent", either my parent(s) or myself as a parent maybe) and it will fill a place in a bridi like any other sumti. doirirni = doi rirni (two separate words even if you don't write a space between them) is a vocative you can use to address your parent(s).
Grammar and morphology issues aside, do you mean something like "Now I know all you loving parents are hardworking decent people..."? Or something like that? You can use {doi} vocatives to indicate whom you're talking to. {doi rirni} means "I'm addressing you, parent(s)," but on the other side, if the audience knows who they are, it therefore means that you, the audience, are parents. You can do something similar with {mi'e}, but I don't really see how to fit that in naturally. I don't think I understand the context of the question in this matter. Information incidental to something that's already being mentioned is done well with {noi}.