Kaiserin makes a very good point. R&D is mucho importante
Now for something I DO know about. Yes it is important to make readers feel for your character let it be like, dislike, hate, disgust etc etc and so on and so forth. In fact if the protagionist does not have any endearing or appeaking traits (even a darker character can be interesting to a reader if done well) chances are people will walk away from the story. I've seen tales where you just cannot get on any level with the protagionist and it makes it hard to read the story. The big question ye asked yourself is "Why should we care?" Even with my own OC I am working on, even when the protagionist becomes the antagionist he is still appealing as a character because you understand why he's turned to the dark side (a little chiche phrase there but its universal).
You see I am simply one hell of a Nobody