As title says, I will to make it by myself sometime, but as for now, I have no clue how to start with it. Some help would be great :)

mmm, at least i think that this could have no sense, and if it is planned to add more Mortar recipes (and many of them use similar ingredients) this could become an issue. (in my irrelevant opinion)

How it can be the issue? If coded right, it would make no problems

well, you are right, if you planify them perfectly there should not be any problems, (sorry)