Questions before publishing my android App

Question

1. Should I add keywords/tags to my description? I saw many apps have them but not sure if they have any purpose.
2. I have in my app few buttons that will show interstitial ad, not to many I don't want to annoy users who download my app. Now since It gave me error duplicate variable, I have 5 different ad requests variables, is that good or bad? Or nothing to worry about.
3. Is there something I should know before publishing app on Google market?

4. About permissions, is there anything I should know about them? I have Write settings,Access Network State, Chang Config, Modify Audio Settings and Internet.

5. Anything to add in Manifest?

Answer 1

1. Yes you should, it helps search engines and others to find your app easily
2. Personally i don't think you should remove it in the starting, like you may put ads in your app after some days but for some time leave ads to impress the users and not annoy them
3. a. https://play.google.com/about/developer-distribution-agreement.html b. Make sure you have your credit card handy to pay the $25 registration fee in the next step.
4. No, i don't think so
5. Go through some of them and you will know(https://developer.mozilla.org/en-US/Apps/Developing/Manifest, http://msdn.microsoft.com/en-us/library/windows/desktop/hh848036(v=vs.85).aspx)