"Did the Force assist Landru in saving his people" and "Was Landru evil" are two very different questions.
The first asks about method, the second ethics. A third question--did Landru use the Force or did the Force use him?
I can't decide on if he used or got used by the Force. Was he evil? Yes.
I don't mind Landru being a sociopath that destroys an entire planet. It's very dark side. You can be a Hannibal Lechter-level sociopath and still manage to create good from thoroughly evil acts, intentionally or unintentionally.
Just my opinion, fwiw--Sanji's method of death bugged me a bit, probably because I always feel Jedi deserve 'noble' deaths if they really have to die in stories. It's like even in death they should be contributing something positive to life.
Sure, 'bad' deaths happen in real life all too often (DUIs, GSWs, etc), but SW isn't real life. My 2 pence.