I can see my nickname there still.
Anyway... The history is very long. I will try to be brief.
If I'm not mistaken, LP0 was only a playground for testing and learning for Indinera or maybe even only a teaser, since he loved to tease the fans a lot. But, heck, eventually, 3 Stars of Destiny came out years later, following the book much more strictly. And which also explains why there is so many things that doesnt match with Laxius Power 1, since LP1 was loosely based on 4 Stars of Destiny, Sanguine Lady (was the name right?) which is about Wendala, and other of his works. By the way, someone go and kick in the ass Indinera and tell him to re-release the books, since I never got a single one 10 years ago when I was still a kid with no money of my own ffs.
And, yes, you got it the other way around - the games are based on the books, since he wrote stuff way earlier than he started to make games. Actually, I think he said he got into game making because he wanted to express better what he had in mind.
As for Laxius Force being called Laxius Power 4... oh boy, was this a big thing back then...
At the beginning, he had a plan for a single large game, way larger than LP 3, which was obviously called Laxius Power 4. But then he renamed it, followed by what he announced to be a new trilogy, since a single game would be way too much to handle. And, at the very end, he decided to go commercial with the games and little by little he transitioned to commercial making, leaving behind the first trilogy and, eventually, the forums, creating a whole new site and community from scratch.
Also, what you are looking at, is a page of the old forum, after which a new one was made, since this hosting was terrible. Alas, the new one wasnt much better, but, hell, it was a place many of us called "home"