Objects can be made up of multiple elements, Perhaps the terminology is different in Maya, I don't know. The buttons as floating geometry would be a good example, they'd be a part of your character mesh, but still separate, thus not welded into place. The problem with you joining everything together is that your edge loops…
Oh yeah, I completely forgot to comment on the creases... can you not just take care of that with the texture? You wouldn't normally model in creases for a low poly object. Baggy jeans for example would have the silhouette of looking baggy, but the creases/surface detail would be dealt with in texture. As for altering your…