if you're able to entertain an idea without accepting it, Thunderbolts project has hours of interesting content and some compelling if controversial theories. if the notion that some of your core beliefs are wrong bothers you that much then you'll appreciate the rationalwiki for saving you some time, I guess.
Thunderbolts definitely has (big!) issues: I would say it's a mix of some under-appreciated but real science and a lot of loose theorizing that lacks the mathematical rigor, data analysis, and peer review needed to back it up. However, the idea that petroglyphs are human drawings of planetary-scale plasma glow discharges is actually a sound theory; and it's not Thunderbolts' theory, in any case. See my comment above:
https://rationalwiki.org/wiki/Electric_Universe