Final Fantasy Hacktics

I wanted to give them custom sprites . My question is if I do that to Alicia and Lavian will I mess up the event to get the lipstick ? I would have to change gen female to example Algus or whatever

That is difficult to say. In the PSX version there's nothing special about Lavian and Alicia, they're normal units. Somehow though in the PSP version they seem to have been given unique ID's or something to make them activate certain sidequests.