Change "even though its important" to "Even though it has an important" This next one is a common mistake for English speakers. While "because" is often used in informal conversation to start a sentence, it is widely viewed as incorrect to start a sentence with "Because", as it is a conjunction that depends on information found in a previous clause. A sentence with "because" has the effect in the first clause, then "because" and the cause of the effect in the second clause. If you start a sentence with "because," your reader is left wondering what effect was caused by whatever reason you describe. This is relatively easy to fix, by replacing "Because" with "In light of" or changing the order of your clauses in the second sentence to say "Homework became an easy way to make students hate learning, because of its unacceptable amounts and types, instead of a way to develop their skills." Also, I agree with the previous commenter that "has become" fits the situation better and sounds better than "became." Stylistically, "not giving daily homework" sounds better to me that "no daily homework," as the previous statement could be interpreted in a couple of different ways. (It could mean that the second type of homework is the best --they use this phrase in infomercials a lot-- or that the first type of homework presented is superior to the second. I figured that you meant it the second way.) It's a tiny detail and the way you have it is understandable, but it could be clearer.

Personally, as a native English speaker, I have never used the word "whom" except to look up the difference between who and whom. I have heard my English teachers use it occasionally, but certainly not in all of the situations where it theoretically "should have been" used. In extremely formal writing, as in college/job applications, go ahead and use whom if you want. It will make you sound "smart," but you should be wary of using it in conversation, as it can also make you sound like a snob.