So in the third book, Left Hand is a sniveling fat guy who wimps out of everything and is basically only there for lame, non-funny comic relief? I only compare between the two films, and in both the Japanese and English language versions of the first film, Left Hand is a wisecracker, but he sounds quite malicious and so forth, and isn't such a coward. I can't stand the English Bloodlust version, at all, especially all his dialog. The original Japanese dialog, which I've read snips of translations of, make Left Hand out to be more like in the first movie (and I believe he was voiced by the same person).
As for the first VHD flick being different from the novel... Again, I didn't read the whole thing so I can't accurately compare, but VHD '85 as a stand-alone movie is downright phenomenal in my opinion. One of my favorite films ever. So much mood and coolness, and the Japanese version is so much better, especially considering Magnus Lee doesn't talk at the beginning when Doris runs into him, which makes that scene so freaking eerie.