I had a video out where I just recorded some GTA Gameplay and I was very Vulgar, which people seemed to like, but it made me feel really guilty resorting to harsh words inorder to get views. Should I find a balance of aggressive behavior and being polite?
How do you know that profanity will give you more views? Personality isn't something that can really be figured out until you actually go into the creator's video (unless many viewers already know you). Besides that, correct me if I'm wrong, but based on that sentence, it seems that getting views/likes comes before figuring out what content you really like to make. I'm not saying that you don't/can't do both, but I think your primary concern should be creating the type of content that meets your standards, then see how you can convince others about it or find an audience that likes it.
No need to feel guilty about it. You're still experimenting, and that's great!
You should continue to find and establish the direction for your channel and its content; it's not so much a case of deciding whether to be more polite or aggressive -- just be yourself. I know that's pretty cliche and overused, but it definitely fits the situation.
Don't resort to doing things for the sake of chasing views. Honestly, views and positive reception should come second to the actual content. Catering to your viewers is a great thing, but just make sure it isn't the the force that drives what content you make.
I just want to better understanding what people like.
As for better understanding what your viewers like, you could separate the videos that were generally well-received and the ones that weren't. Unfortunately, the thing about this is that it's too general; how do you know exactly what it was about certain content that people liked/disliked? Did they just like that it was a GTA gameplay? Was it your personality? With nothing but likes and views to base this from, that can be pretty hard.
Based on your videos, it seems that you just started uploading content recently, right? If so, then no worries; you're essentially establishing an identity for your channel right now. If you've been making videos for quite a while, however, then people might not like you going off on totally different directions than you established.
Keep experimenting and doing more of the content that you do in order to get a better assessment. We don't actually know if the people that gave some videos a thumbs down disliked for the sake of doing it, or actually didn't like the content in the video. The same goes for likes!
Remember, at the end of the day, there's a niche for a lot of content on YouTube. If your current audience doesn't like the content that you enjoy making, you can still create that niche and find that audience. I'm not saying it'll be easy, but it happens! Content first; views and viewers later. They're both very important, but one is more than the other.