The correct version of it

would be He’s got more wealth than that of Steve, John and Michelle put together?

And he’s got more

wealth than his wife’s, John’s and Michelle’s, all of It’s Aiming On. (as you said), and He’s got more wealth than He has?

“That of Steve’s, John’s and Michelle’s”, is wrong — “that of” already indicates possessiveness so it is incorrect and redundant to add “‘s” to indicate possessiveness.

If Steve, John, Michelle, et.al., want to say “than that of Steve, John” then that sounds more natural to me but I don’t have a technical

reason to explain it.

Either are acceptable. I am not familiar with the difference between think of and think about, either in their formal meanings, or in their contextual or regional usage.

I would use “think of with,” but that’s very personal preference.

Does it matter when you ask people about the service in general, and when you ask them about an instance of the service, I mean, a particular occasion?

If you want to get the details of a question, then you should be more specific in your question, e.g. What

do you think of the service you received last time you stayed at The Glitz-Glamorton Hotel?

What is the difference between a vs. a vs. a v. a v. a v?

What do you think about the service you have received during your stay at POK Hotel?

How can the form of the question affect your personal performance in survey. Think about whether your survey should be more formal, or should I ask just one question informally? If you want the responses to be open-ended, think of or brainstorm are probably good phrases to use. If you are looking for a specific aspect, mention that in your question, and use another phrase besides think of or think about? What

would you rate the service you received the last time you stayed at the Glitz-Glamorton Hotel?

What made you stay at the Glitz-Glamorton Hotel?

Did the staff at The Glitz Glamorton meet your needs during your recent stay?

Was the hotel staff friendly and helpful?

What needs improvement, based on your recent stay at The Glitz-Glamorton Hotel?

What should I do if I am a vegetarian?