Controling forex EA's license period

Hello. Please provide me with details about your needs to estimate properly. 1) to what side license is linked: to account number or to computer? 2) what is your license representation: string code of file? 3) do you need to block licenses manually, or they only expires automatically? 4) do you need additional options for licenses: only demo/real mode, pairs limiting, open orders limiting or something else? 5) do you need billing system? 6) do you prefer web service, or you want to use your computer only? 7) do you need any reminders about expirations? Ready to listen about your suggestions and work. I renting my expert too, but I using license code generator which contains account number, expiration period and all options encoded in it.