H4 visa along with B2 tourist visa

[satyaworld]

Hi Team,

Currently I am holding H4 visa in my Indian passport and working in NZ. My
H4 visa validity is going to end in coming November 2019. And I have plan
to travel in coming December month 2019.

Note: My spouse is currently holding H1B visa and validity is going to end in
same November month and have plan to apply for the extension.

query1 : Can I apply separate B2 tourist visa to travel USA ?
query 2: Can I able to use same H4 visa along with extension applied copy
to travel USA?
query 3: Applying B2 tourist visa may create any impact in my existing H4
visa extension?