In Sefer Dvorim the Torah does not spare curses for general misbehaving or misbelieving, etc. In my understanding, the Torah presents a clear system of reward and punishment (Rambam's principles) - do a Mitzvah and you get rewarded, do a sin and you're punished (Ki Tavo for example).
All these curses shall befall you; they shall pursue you and overtake you, until you are wiped out, because you did not heed the LORD your God and keep the commandments and laws that He enjoined upon you. They shall serve as signs and proofs against you and your offspring for all time. Because you would not serve the LORD your God in joy and gladness over the abundance of everything, you shall have to serve—in hunger and thirst, naked and lacking everything—the enemies whom the LORD will let loose against you. He will put an iron yoke upon your neck until He has wiped you out.
The LORD will bring a nation against you from afar, from the end of the earth, which will swoop down like the eagle—a nation whose language you do not understand, a ruthless nation, that will show the old no regard and the young no mercy.
It shall devour the offspring of your cattle and the produce of your soil, until you have been wiped out, leaving you nothing of new grain, wine, or oil, of the calving of your herds and the lambing of your flocks, until it has brought you to ruin.
It shall shut you up in all your towns throughout your land until every mighty, towering wall in which you trust has come down.
What part do those general and unrelated to specific Mitzvos curses play in our reward-and-punishment Mitzvos system?
NB: Please don't bring Kabbole saying all those are Brochos, we just don't know how to read it properly.