They absolutely can. Take a look at http://reactivex.io for implementations in lots of imperative/oo languages. Functional reactive programming can also be done in these languages but may lack some of the convenince of a functional oriented language
Could you elaborate on what you feel is currently grunt work? Do you mean the difficulty in building and debugging complex models or something more abstract?
Honest question - why is that something to avoid? What does the floating point representation buy you that say an int64 doesn't, with the same choice of units ie. 1 = 10^-6 dollars?