Perhaps his work is unbiased as you say. However having read many books with similar claims, presentation, and general background like this book I'd say it's rather more likely that he's interpreting the Bible according to a modern American evangelical context.
It's also probable he's from a less mainstream American religious strain like Seventh Day Adventists as they eschew many mainstream Christian practices as pagan.
So yes, without further other indicators of academic rigor, I would decline. Though I did initially check the link curious to see if it had indicators of any academic rigor as I do find the topic interesting.
> It's also probable he's from a less mainstream American religious strain like Seventh Day Adventists
He's not. He identifies as a Christian, as prescribed in the Bible—not of any denomination. Seventh Day Adventists believe in recognizing the Sabbath, but they also believe (and are baptized swearing in that belief) in the prophetess Ellen G. White.
