What is your opinion about these?  (You are presenting more than one sentence. Therefore, you would like to receive someone's opinion on "these" sentences.)

How What do you think about ...? (We use "What" to focus on a topic of discussion and ask for specific information. On the contrary, we use "How" to ask the way something is done OR the state or condition of something.)

What is your opinion about ...? (There is a slight difference in emphasis between "think" and "opinion". We provide an opinion after thinking about an issue. When we are "thinking", we are still processing about an issue mentally and forming an "opinion". An "opinion" is our view or personal judgment, which may or may not be objective and factual.)

How do you view this issue?

She has her own perspective on this matter.

Do you have your own perspective on this matter?

(A "perspective"  that you offer is your point of view or personal analysis of an issue.)

What is your attitude to life?
What is your attitude to your work?

(An "attitude" is a tendency to interpret things in a certain way, and behave according to that interpretation.)

We all appreciate a balanced outlook on life.
What is your outlook on life?

(An "outlook" is a person's general attitude towards life -- an "outlook" can be positive or negative.)

Hi Willson, 

As you can see, these words have similar meanings, yet they have nuances in their usage. 

I hope this helps.
Cheers, 
Lance