Actually I really liked Paulo Coelho. Maybe I was in a situation that made me blind to its tackiness. Back then it helped me in accepting my own heart, because I had been overriding it frequently. I had locked up too many emotions. Also - in accepting tackiness and ignoring public opinion can you start embracing yourself. Don't try to be "cool", or adhere public views, when on the journey to yourself.
Yes you should take your brothers word seriously - at least to the degree that he gets the respect that any human being deserves. Sure, you can prove him wrong and an idiot, but try to listen and not just "nod him off". That would be very poisonous for any relationship
In spotting weakness in others and being presumptuous can you conjure great strength instantly. This is very useful in some situations - but mind, it will turn you into a very lonely and hated person if you use this "cheat" longterm. True strength is not found in pursuing the light (running after public opinions), or embracing the darkness (spotting weakness in others), it is found by becoming the light yourself. How do you do that? If I knew the answer, I probably wouldn't be sitting here, but I'm sure reading some books can help.
Nourishing. By that I mean a lot. Giving attention. Giving praise. Giving time. Giving materialistic things. These are all good deeds, when you give them away - but it is very important to not give away more than you can.
Hm. As for cost/effectiveness calculations, I am not so sure. But any process in nature is very aware that resources are scarce, there is no room for uselessness. I am currently on the quest for fulfilling this natural order of things, by reading some Marcus Aurelius. I want to be a good leader someday, and leaders are constantly faced with difficult decisions where cost/effectiveness plays a very important role. The right decision is not always the happiest one.
Also mind, there's like three words: efficacy, effectiveness and efficiency. Whoa...