I have some ideas about your coin, How about I start mining it with many mobile devices just to get to generate the next block every time for myself? Then someone else would come and beat me with a higher numbers of mobile devices to generate the next block, Then the next person would do the same and there we have yet another arms race of mining. This does not seem to work as you would like to say it would. It is nice on the paper though, But it is not gonna work.