The Quito airport is about 45 minutes outside of the city so you won’t find any hotels within Quito that are near the airport. If you want something close to the airport for the nights before and after your flights most people use the Quito Airport Suites (airporthotelquito.com).
The suggestions for lodging in Cotacachi are still good with the possible exception of Land of the Sun. It is under new ownership and I’ve yet to hear good reports.
I haven’t been to the coast for some time, so maybe Suzan or Edd can chime in about Salinas.