Sorry to break it to you, but it's not possible.
You can't put this game on the App Store since Nintendo has Pokemon games up already(in part with DeNa) and they will definitely know what's up. They'll shut down the game due it being bootlegged.
For Google Play, you might have a small advantage since there are alot of user-made and bootlegged games, but that's not all 100% possible.
And not if anyone is noticing but this thread is duplicate to mine:
http://pokemon3d.net/forum/threads/9324/
the great thing about android is that you dont need to have it in the app store to play it, since you can download and install it as a 3rd party app, and having the app (possibly) download updates just like the launcher on windows. since IOS is so freaking annoying with tons of bureaucratic loopholes it's not economical to have an app for iphones.
knowing how uptight google has been lately with the copyright laws and such they will take it down immediately since the app is in direct infringement of nintendo, so third-party is the only wat to go if we cant get it to goo on amazon's app store, which nobody uses anyways.
on another note, looking at your post, i like some of the topics you bring up.
also it doesn't have to be for just tablets, most phones these days could possibly run the app, but it will take up space, so being stored on SD card space will be a must.
as for controls, i think something simple like most emulators would be a transparent overlay, with the camera manipulated with another touch. sorry for duplicating, i did not see your post. it was quite old though.
i would love to get Nilllzz's input on this too. i think this is a very possible project and would like to help out.