It is considered invalid by many Christians. It's also considered valid by many Christians. The closest you'll get to an objective answer is to look at the Amazon book star-reviews, which is what I encourage you to do. It indicates that the book is very polarizing. And I suspect that the answers which will accumulate here will look very much like the written reviews there.
There is absolutely no way to "decide" whether Lindsey's view holds up, so the question is impossible to answer. As you may predict from the book's reviews, you are sure to get quite polarized answers. For example, a random Catholic from the internet says:
I recommend Catholics stay away from Lindsey's stuff and go read something by a saint instead.
And from an article on general subject matter:
The Church does not endorse pre-millennialism. The Catechism of the Catholic Church explains: "The Church has rejected even modified forms of this falsification of the kingdom to come under the name of millenarianism." Indeed, the Nicene Creed, which is said at every Sunday Mass, appears to reject pre-millennialism, holding that Christ will return "to judge the living and the dead," not to reign on earth for a thousand years and then judge the living and the dead. Since the Church is not pre-millennial, the question of a pre-trib Rapture does not arise, as pre-tribulationism is a variant of pre-millennialism.
From all this we can only assume that mild answers will range from the mild "well, many consider him ok" that Narnian presents, to the mild "read something better" I quoted above.
Questions you may consider asking instead:
- "Is Hal considered a prophet by any body of Christians?"
- "What is the view presented by Hal in ... called?"
- "Why does the Catholic Church reject pre-millennialism?"
- "Do [insert denomination that you identify with the most]s like Hal?