Dentist for the first time in like 6 years

I went in for my initial exam and x rays for starting at a new dentist (one I hope to keep for a while as he is located 2 floors above my office!) I had more cavities than I care to utter the number of and the start of tooth decay in many locations. There were cavities between my teeth which he said is a result of poor diet choices. I'm going to list some things that we discussed:

• When brushing your teeth it's not about pressure, it's about time, 5 seconds in each area
• He recommended a Sonicare toothbrush and said that would help with my gum sensitivity. Thier office sells them without a markup because he believes in them and wants them to be affordable. I need to inquire what model it is though. 
• Apparently I never was taught how to floss, just told to do it. He showed me how, taking the floss down the side of each tooth once getting it past the point of contact. Also pushing down on the gum a little bit but the idea of flossing is more to scrape stuff off the teeth
• Wait at least 20 minutes AFTER you eat something sweet/acidic to brush your teeth. The acid makes your teeth soft and brushing too soon can actually scrape away parts of your teeth. 
• If you are going to drink a soda, use a straw to keep it off your teeth - that way it just goes straight down your throat without pouring all over your teeth.
• Cavities on the side (between) teeth is generally caused by diet, and not flossing. 
• Probably most people know this but hard candies (when you suck on it for a long time) or gummy candies are the worst. They provide the longest exposure to sweets to your teeth causing the most damage.

I told him that I had begun to eat a Paleo diet which he said would help. I was also informed of dietary studies of reversing tooth decay a while back by a friend who was researching it because one of her teeth is dying and she wanted to see what she could do without resorting to a gap or replaced tooth. Basically the gist is avoiding sugars, limiting fruit to 1 piece a day, A DAY! Consuming fish, bone broth and organ meats as well as taking Cod Liver or vitamin D3 supplements. I have also read some reports of people chewing Trident gum with Xylitol and having cativies go away, or even cracked teeth fix themselves. So I'm reading into this a bit more and I think my plan is to get the two big cavities on my right side fixed because I know about them and they make it hard to eat sometimes (and they are big) and see what I can do diet and hygiene wise (getting a Sonicare and stepping up my flossing)  to reverse the issues, or at least stop them in their tracks. 

The x-rays I got were digital and I read something online that the digital x-rays are more powerful/sensitive than traditional films and therefore can pick up more cavities that weren't considered there before. This can mean better preventative work but it can also mean lots of money for dentists filling cavities that previously wouldn't have been found. I told him I wanted to spend as little out of pocket as I can (I have dental insurance, but it doesn't generally cover that much) so it looks like I'll be getting silver fillings rather than white ones.