In general PVCs and PACs are not harmful. If one could be considered more potentially dangerous I suppose it would have to be PVCs, which if present in persons with heart disease may indicate the need for treatment. I do not remember you having any dx of heart disease.
People, on average, with normal healthy hearts and benign PVC's/PAC's develop other serious conditions no different from the public in general. There is no data that individuals with PVCs or PACs are at higher risk for developing serious health problems. Remember I am not a physician.
PVCs and PACs along with short runs of PACS are a type of arrhythmia to the best of my knowledge. Occasional arrhythmias are normal.
Great input from CrohnieToo. Hope you can decrease your worries about the outcome of your Holter Monitor results.