Learn English – Which is better grammar: “courteous of” or “courteous to”

The problem with "I was wondering what are the differences between A and B" is that the segment "I was wondering" is a complete sentence and "What are the differences between A and B?" is a complete sentence. It sounds funny smushing them together without punctuation:

I was wondering: What are the differences between A and B?

I was wondering, what are the differences between A and B?

The problem disappears with "I was wondering what the differences between A and B are" because "What the differences between A and B are" is not a sentence and the whole sentence is more like the form "I was wondering what these are."

Restructuring a sentence because a bit in the middle is getting too long is okay to do but there are other ways to deal with the same problem:

I was wondering about A and B. What are the differences here?

They are both okay. You can conjoin any two phrases of the same type to get another phrase of that same type. The structure is

I am doing this [[to [get more attention]] and [to [seek for opportunities]]].

where "and" connects two to-infinitives and gives you a to-infinitive that goes with "doing this". But the two lower verb phrases could also be connected:

I am doing this [to [[get more attention] and [seek for opportunities]]].

giving a verb phrase in construction with the "to".