While this might have some value as a minimalist opening repertoire, I think you'd probably be better off exposing yourself to as many different types of positions as possible and learning to play all of them rather than trying to limit the types of positions you get and not knowing what to do in different structures.
My suggestion also helps later on when you want to change an opening - you might be familiar with the ideas associated with a structure, as opposed to never having seen anything like it before and having to learn how to play an all new set of positions.
I have been doing some thinking on a repertoire that deals with a lot of transposing causing study to a minimal study around 1. e4.
Against 1. ... e5: The vienna game
Against 1. ... c5: The alapin (c3) variation (which can tranpose to french advance variation and a line of the caro-kann panov-botvinnik variation)
Against 1. ... e6: Advance variation
Against 1. ... c6: Panov-Botvinnik variation
Against 1. ... d6 and 1. ... g6: Austrian Attack (transpose to each other)
Against 1. ... Nc6: 2. Nc3 variation (transpose to vienna game possible)
Against 1. ... Nf6: 2. Nc3 variation (transpose to vienna game possible)
Against the rest of the openings you can use the traditional openings