1)
For what does he thank Hashem?
1.
Malbim: It is for the good things that he attained.
2)
Why does it say "b'Chol Levavi"?
1.
Radak: After You will unify my heart, not even part of my thoughts will be other than You. Rather, I will thank You with all my heart.
2.
Malbim: I do not thank with intent to request that You continue to benefit me. This is not with all the heart!
3)
How will he honor His name?
1.
Malbim: He will tell his praises and Gevuros.