punctuation - Alternative to Indirect Questions

The syntax for indirect questions is that the verb goes after the subject such as,

I am wondering what the time is.

If not asked as an indirect or embedded question, what punctuation would you use between the two clauses for the following sentence?

I am wondering what is the time.

As a native speaker used to conversational English, this sounds awkward if not incorrect to me, because I frequently use indirect questions (Microsoft Word apparently thinks so too). If I were to verbalize it as in the second example, I would put a pause between "I am wondering" and "What time is it?"
My first question is – is a comma the correct punctuation for the second example? Can a hyphen also be used?

Next when sentences contain more information, indirect questions start to look and sound awkward when read. For example:

I’m trying to find what the best solution to the problem is.

As opposed to

I’m trying to find what is the best solution to the problem.

I know what you’re thinking: why not omit “what is”. Hypothetically speaking, if I wanted to state it indirectly, would it be grammatically correct or good writing to do so?

One last example, keeping in mind the same syntax:

I want to ask when a good time to call back is.

If spoken, I wouldn’t second guess it. But when I read it over and over again, it doesn’t sound right.

I appreciate any feedback and/or expert advice, as well as any reputable sources that address this specific question.

---

I asked this question because I had recently pointed out this syntactic error to a non-native speaker who composes work-related emails to Americans. While the type of punctuation may be negligible, I wanted to give the most appropriate alternative given the writing context.

Out of the three options, which punctuation would be most appropriate for professional emails?

Also -- would the sentence, "I was wondering, what is the time?" by definition wouldn't this be an example of a comma splice? And if you start the sentence with "I was wondering", wouldn't you have to end the sentence with a period?

I'm hoping I can pass on clear cut grammar and punctuation advice while keeping his writing natural and conversational sounding.