If someone has corrupt intent, but does a lot of really good actions and helps a lot of people in need without taking much in return, would you consider them a good person or a bad person?

No, I don't believe it tarnishes their actions. Good actions are still good actions regardless of the intent.

For example, the entire concept of "Necessary Evil". Which is ironic since I've never heard of anyone speak of "Necessary Good".

If those corrupt intent didn't happen for real then yes the person is good. Maybe the person is trying to get rid of those corrupt intent by doing a lot of really good actions and help a lot of people in need.

No, I do not believe that the intent of a Character tarnishes their actions. While their motives might not be pure, the fact that a good deed has been made remains unchanged. Of course, that wouldn't made me consider them a Good person as well though. Unless they seek Atonement and trying to control that corrupt intent. This changes things a bit. In the end, it really depends. At that point, I could say that I consider them to be more on the Neutral Side rathen than Good or Bad. Speaking of which, those kind of Terms tend to get generalized a lot as they can be pretty broad. Opinions on one's intent might vary. So, there is that as well !!!!

A case by case scenario honestly. A good person can have a negative intent and a bad person can have positive intent. It depends on a variety of factors. I consider the person in question an underhanded person. He/she could legitimately care about themselves and not care about the implications that are happening good or bad. That kind of a person would then be only out for themselves and neither good or bad. There's alot of gray areas but due to people philosophical,religious,etc viewpoints people generally pick sides. So what could be seen as evil could be seen as being good or neutral. It really depends. Until further analysis on said person. I'd argue and say intent of a character tarnish their actions generally. But overall the main point of this should be view as a case by case analysis for anyone.

I see them as a quote en quote “salesperson”