What precautions should I take when burning pine firewood?
There is no hard and fast rule.  A few fires a season may be OK, a daily fire that is not very hot may not be.    Creosote builds up from vapors condensing on the interior surface of the chimney, so the amount of buildup will depend on how hot the fire is, chimney construction, and possibly even what time of year the wood was cut (there is more sap in the wood in spring, for example).

I would definitely discuss this with your chimney sweep; if they are knowledgeable, they can help assess the chimney construction and probably give you some tips on how to minimize creosote buildup with your particular configuration.

Keep in mind that chimney fires can be extremely dangerous to your house, so it would pay to be conservative.