As ones reputation goes before one, then this could be your advantage. People like nice people, it just depends on other factors...
Honesty is sometimes a blunt instrument that blodies more than it cuts. Its sometimes best not to tell people what you think, just tell them what they want to hear. You can't go about telling people what you think because they will think you are complete twat. If credit is due give it.
If critique is needed be tactful. If someone scratches your car, beat the shit out of them. You might think that speaking your mind will endear you to people and others will see you as a paragon of decency but this is not the case. What you say and do always has to be adapted to the people and situation.
Don't sweat the small stuff, seems you have too much time to mull over this kind of thing instead of concentrating on self improvement.
You ever seen Kung-Fu the Movie when Caine is asked by the Chinese railroad worker 'newcomer why don't you speak?'
He replies 'if ones words are no better than silence one should remain silent'.
Sometimes this is a good idea. To be honest the less you say the more powerful you appear and people will always be trying to interpret what you mean when you do actually speak. People who constantly waffle and chunner garner little respect, they are too obvious, too famililar and boring. When you speak, make it open ended, vague and sphynxlike if you want to impress people. Also don't take people's sides, avoid arguments and control the emotions.
Half of what people do is to get a reaction out of you. When someone is trying to push you, often to get a reaction don't act forcefully back, just chill and stay calm. That's the best way. Going hammer at tongs at people and over-reacting just triggers off a chain of events which is well out of proportion to the original.
I was a little like this in my teens. Constantly churning up arguments and never feeling in control. It can be miserable I appreciate that. Just a few simple things concerning what you say, think and do and you will be on the right track. If you don't feel in control its likely that your idea of power is all wrong. Instead of constantly reaction to situations start to control the way things happen youself. Instead of having to think of a cool reply to some comment a friend or girl makes. Start making your own.
Get yourself a copy of :
The 48 Laws of Power by Robert Greene.
Most of the stuff I put here is straight from that book, by the time I got round to reading it, I had learned most of it already the hard way by trial and error. You could save yourself a lot of effort by picking up a copy.