With an absolute monarchy, two modern universities in one province are enough to bring your public order way down, so don't build more than two. If you want to have more (quite necessary for a proper tech advance rate) build them somewhere else.
Otherwise, watch your industrialization, the lower classes get really pissed off if you've got more than three-four steam engine factories and/or mills in one province and nothing else to quell the

If anything, I've found that it's much easier to have an absolute monarchy. You can always throw the gay ministers out.