Vine's work is noteworthy for its scope, not its accuracy. He starts his research already convinced religiously of the premise that the entire Western culture is in apostasy, and has been for 1600 years. He is of no particularly impressive linguistic education. His work is of note because of its exhaustiveness, not its excellence. And he didn't come to his flaky beliefs as a result of his work, rather, he initiated his work to support his flaky beliefs.
Vine is writing in 1985, (according to you; I believe he was long dead by then, actually), and obviously belongs to a crackpot sect, given his labelling of the entirety of Western Christianity as apostate. Using a source who starts from the premise that most of Christianity is apostate to define a term which you think demonstrates that most of Christianity is apostate does not grant Vine much credibility.
So, we must look at Vine's assertions. Where does he get his ideas? Unfortunately, Vine was not scholarly enough to tell us. "Chaldean" refers to a region of the northern Persian gulf. The only ancient reference to Eostre is in the writings of a 7th-century historian in England. How can Vine possibly know the two are related? Certainly Ashtereth and Eostre are not obviously linked by their names.
What then? What so filled Vine that he could declare apostate most of Christianity, and also make the completely unfounded leap to declare that Eostre was Astarte? Their names are hardly that similar.
It's also interesting that Vine chose to relate Eostre to Astarte, and not any of the other gods who have been suggested to be related to Astarte, such as Ishtar (which seems more similar to Eostre), Ashtoreth, and even Aphrodite. Could it be because Astarte was a name used by Satanic cults? Could Vine be pushing (*gasp*) an agenda?
Perhaps Reverend Hislop's research is acceptable to you?
Easter being Pagan is not exactly ground breaking stuff.