Partly to the content Harem is what describes that he has access to several women, 3 or more to be exact, as you say yes, it's fine, but with respect to the Harem ending it is that the MC can stay with all the girls, especially the main ones, in your case all the ones on the banner , so that would be the question, can the MC keep them all or will he have to choose one?
Personally I would prefer her to have her harem, but it wouldn't be bad if there could be both options, that is, a final Harem and an ending for each one.
Regarding the lesbian thing, as long as it doesn't happen without the MC, it's fine in threesomes and if you decide to implement that, make it so it can be avoided, so the player can decide what happens and what doesn't, this as a recommendation.