Here is a general answer. 1,2, and 3 are basically the same question. You are asking a person how they are doing right now or in the recent past (maybe a few days). You could answer "I'm great, everything is fantastic" or "I'm feeling bad because this week at work has been very stressful"
'How are you doing?' is the full version and slightly more formal. 1, and 3 are just slightly more informal versions of #2. Again, they are just asking how someone is doing at the moment, based on the recent past.
#4 and #5 you would use if you are talking to someone you haven't talked to in awhile. Maybe a friend you haven't seen in a few weeks or months. You aren't as worried about the very recent past (if they are feeling good today, or if yesterday was a bad day) you are asking about how things in general have been since the last time you spoke. They might answer with something like "I'm doing great, I got a new job and its a lot of fun and pays good money", or "I've been doing pretty horrible lately. "I lost my job last month and cant find a new one, and my girlfriend broke up with me last week".
'What's up?' is a very informal greeting that can mean pretty much anything in English. We use it to just say 'hi' to a friend, or ask how they are doing now, or how they have been doing in the past.
If I was at a party and I saw my best friend I might say 'whats up', and he might say 'nothing', or 'work has been killing me lately' or he might just say 'whats up' right back to me.