We praise God because we give Him the glory that is due His. Everything that goes well, or even bad, is ultimately for His glory and we shouldn’t bring ourselves up to a higher position in the eyes of men by what He has allowed to happen.
The second part, I feel that’s really abusing the free will God gave us. It is true that doing evil is by your own will, but the person seems to be using that as an excuse to do what he/she desires. It’s like committing a sin knowing that God will forgive and using that as an excuse to commit more sins, which is definitely in the wrong. Christians should not be taking advantage of God.