Error: The steady state has NaNs or Inf

[jpfeifer]

Your exogenous processes are inconsistently defined. Sometimes you are correctly using an exp()-substitution, sometimes not. Only do an exp-substitution once the model works.
I would recommend going for option 3 at

Question about understanding irfs in dynare

To be more precise: it depends on how the variables in your model are measured. As @stepan-a says, Dynare conducts a linearization. If you for example have a nonlinear model and your model variable is simply the level of output, the IRF will measure the difference between the variable and its steady state (or its mean at higher order). This is the case with https://github.com/DynareTeam/dynare/blob/master/examples/example1.mod In contrast, if your model variable already measures percentage…