I've been experiencing some of the same problems: PACs, PVCs, and mild tachycardia (all diagnosed benign after much testing). I've been on a beta blocker for going on 6 weeks now, and I've got to say that it really does help. It's like putting a pillow over a speaker - that incredible skipping feeling is well dulled. I finally found the right dosage (still fairly low) and it seems to be working great. In my mind, the slight possibility of a side effect is outweighed greatly by the decrease of my symptoms and anxiety because of them.
I know that there has been much in the news recently, specifically that study in October by a Netherlands group, about beta blockers not being effective needs to be researched better. It is still greatly effective for those who NEED it, those with issues of tachycardia, high blood pressure, etc. If your concern is that great, you should discuss it with your doctor, or even a cardiologist. Get a second opinion if you need to. But remember too, that generally when your doctor prescribes a medication like this it's because the likelihood of you feeling better with the med outweighs the likelihood of the possibility of a side effect.
I'm not a doctor, and I'm not going to tell you to take the med or not, but I CAN say that it has worked well for me. I also do not plan on being on it long term, nor does my doctor think I need to, so you may want to take that into account too. Good luck! Let us know what you decide and how it goes! Prayers to you!