I cook over wood most of the year, either in the fireplace or on the deck on the BBQ. I know that the woodsmoke gives the food its flavor but you have to do it right. Green maple is terrible to cook over....dry maple is OK, as long as you have a HOT fire and control the heat by moving the meat...
The creosote in your firebox is nothing more than smoke that has condensed. I see people with their little "smokers" that are nothing more than a fire at one end and the smoke is diverted over the meat at the other, either "hot smoking or cold smoking". Never done either but have enjoyed the results of both. (well, I have cooked rainbow and lake trout over a cool smoky fire for 3-4 hours)
My idea would use the cooler smoke, after any creosote has condensed....