But the 30 day rule may also work for you. I've read that the score is the average of only the last 30 days, so if you drive clean for that long, the dings should fall out of consideration.
Regarding those FCW's they are the worst, especially when the car is hallucinating them. They do attenuate as you add miles, though the miles that day form the daily score, and future miles won't change that. Future days' miles will attenuate a bad day, but a bad FCW ding can be bad, bad. My opt-out was after my wife scored a 42% one morning. I went out to add miles and got out daily score up to 84, but it takes a lot of 100 miles to make up for that. Hence our try at the opt-out. Since then 100's are the norm, but it does train one to pay a lot of attention... Or use auto-pilot a lot.
Good luck! And hang in there. No one in the US has been added to Beta since December. Perhaps Tesla has enough already to find most of the bugs and edge conditions. On the other hand, the cars will have to handle all of the edge conditions, as well as all of the crazy and careless human drivers, so lots more "Beta" may still be in order before it becomes production standard.
What I mean to say is that no one knows if a good safety score will ever get you into Beta, or if it will happen later on today. Have no expectations and you'll have no disappointments. ;-)