>>1885212once you combine the vertex there shouldn't be any gaps, don't worry if it happens though, pick the alone vertex and see which one of the already combined ones can fit with it and re-combine it.
now for the nipple, in this texture, the nipple is not on the breast, so we have to move the nipple mesh in the uv mapping and put it where it is, but at this point doing that will fuck up the mapping of the entire breast, because of the shared vertex, so you have to select the areola mesh and click on separation of the shared vertex on the selected face tab, and then select only the nipple mesh and click "is taken to a new material" on the same tab
now you can freely move those nips. and with that you are done with the breast gaps. check if the weighting doesn't have any problems, for this model the spine bone has complete control of the torso mesh and the breasts, so the new mesh should be 100% too. for the vag you can use the same panty that comes with the model, it has the same vertex position and all, so you need to erase the unnecesary vertex and combine it, again check the uv mapping plugin before you do that and put the vag mesh in the gap that the crotch should have. once you done, pick three of the vertex of the vag and move it up just a little to give it a slit.
this process can be done with any model, you just need to see how it can be fit, sometimes you don't even need to import meshes from other models; clothes usually are done with the body on base so they could have the necesary mesh. the complicated part is when they have physics.
this could take some tries but once you can make it look good/decent for you, this could open a new world of options for different models that the creators cockblock you with erasing their parts
