1) What can be mahr for mutah who live in different countries and the money/gift/meal cannot be sent.
Can it be something else? (It is done for engagement period to allow boy girl to speak properly)

2) Also, wil it be sinful to get sexual thoughts about the spouse when mutah has been done with a condition that its for talking purpose?

1- The Mahr can be anything you agree upon. It can be money, it can be a gift, it can be a meal, it can be anything. It has to have monetary value. You can pay it whenever you are able to. Or you can make a bank transfer, or send with western union or paypal. It can be any amount.

2- No. Once the Mut’ah contract has been done, it won’t be a sin to have such thoughts.