Quiz website

Hi, i want to start a quiz website it would be great if you can provide answers to the following questions.

1: can i copy content from other quiz websites?
2: adsense approval easy or difficult?
3: can you suggest wordpress theme/plugin?
4: if i want to target one country shall i go with country domain? like .us/.uk etc (will that help in local seo)? or shall i go with .com?
5: what should be the backlink strategy?

1: Paraphrase the questions
2: Difficult
3: You can find lots at Google. This should get you started: https://wordpress.org/plugins/wp-pro-quiz/
4: .com works perfect
5: I'd buy guest posts

If you copy content, you risk plagiarism and shuld you get found out you risk a ban from Google.
I would go with a universal .com
for the wordpress theme... simple is key... find one that is easy to customize and avoid lots of graphics especially when you are just starting out
I believe adsense approval is universal as long as you have relevant content and a good amount of traffic sooner or later you will get your approval
back linking strategy - use forums and write some content on article directories that revolve around the questions you need to address on your new site..

All the best

wow!!!~~~~