Complex sentence: Johnny Depp was the only actor Burton considered for the role, who signed on without reading the script under the intention on going with a completely different approach than what Gene Wilder did in the 1971 film adaptation.
Split into simpler sentences: Johnny Depp was the only actor Burton considered for the role. He signed on without reading the script, under the intention of going with a completely different approach than what Gene Wilder did in the 1971 film adaptation.