Yes. The revisions you have made are correct because each question is a complete interrogative sentence. In which case, the question mark functions as terminating punctuation (Chicago uses the phrase "terminal punctuation") to indicate a "full stop."

(I think it is fair to call the "full stop" as a linguistic element usually punctuated graphically by a period, and therefore "full stop" is frequently used as a synonym for the period.)

Consider that the question mark does not always indicate a full stop. It's appearance in the context of quoted material is the obvious example:

"What the heck are you doing?" Jake screamed as he entered the room.

Chicago says, however, that "A question mark should [also] be used at the end of a directly interrogative element that is part of a sentence," as in these examples:

How can Israel and Palestine be reconciled? is the question on every mind.
What the heck for? she pondered.
As he asked himself, Is it even possible at all? he looked on calmly, hiding his surprise.

Additionally, there are cases in which multiple question marks may be used in a series of fragments in which each fragment functions as a separate question. Consider this example:

When a manufacturer knowingly sells widgets that meet government standards but are defective, what are the manufacturer's legal responsibilities? moral responsibilities? financial responsibilities?

In this case, we have two question marks that do not function as terminating punctuation (full stop) and a final question mark that does function as terminating punctuation.

But consider that this is a sentence that intends to communicate a rhetorical reinforcement of the act of questioning itself. Certainly, many editors would recommend this instead:

When a manufacturer knowingly sells widgets that meet government standards but are defective, what are the manufacturer's legal, moral, and financial responsibilities?

No actual meaning is lost, but there is certainly a rhetorical quality that has been eliminated.