yes you can, you need to have same mobile number as you register with them, at the time of registration online they will sent one time password on to your mobile, to check the authentication of yours, after that it is not required. Let this some one do it for you in back home, and send to you the credentials.
No problem,if you use also it does not matter, you tell some one to register online back home and send to you the credentials for log in for air tel website.
NRI's leaving in GCC countries can use PAYTM website for recharge your DTH and mobiles of INDIA. But for addition of channels or remove of channels you need to call them from your country where you are leaving.