I only have throat irritation when I use a juice that has more than 40% PG. I've been vaping for over a year (close to 2 years) and I seem to only be sensitive to PG juices.
I did have the tonsil stones / weird throat irritation when I quit analogs, but I think that was just the toxins leaving my body.
The key to vaping happiness (I've found) is with keeping your hardware (cartos/attys/clearos) clean, and drink plenty of water (especially this time of year, if you live in a northern climate - indoor heat is brutal on your sinuses)