I'm trying to understand various sentence parts, clauses, etc. So I would appreciate some help:

1) In this sentence: "One reason why we shouldn't spend so much money on the armed forces is because there are other important areas we could use the money on."

Could someone help me with breaking down this sentence to various parts. E.g. where is the independent clause, the dependent clause, the abverbial clause, relative clause, noun clause, etc. It would be a great help. This sentence is quite complex. I would like an explanation of the "is" and the "because" especially and what it's in the position it is.

2) In the sentence "He scored a great goal by using his hand." Would "by using his hand" just be a prepositional phrase or could it be defined/explained in other ways.

Thanks. Appreciate someone's help.