Thank you all for your replies. I will keep my fingers crossed and try to run the fastest I can

Is the terminal to terminal shuttle in Narita open to all transit passengers, or are the shuttles categorized by alliances... ie., if it is open, then the interval between shuttles is less than 10 mins. during my estimated time of arrival, which is not bad.

Also, do you have to tow your check in luggage with you in the shuttle and recheck it at the terminal 2, or is there a luggage transfer station at terminal 1 which will do it for me after I do customs and deposit my luggage there (provided I get Delta to check it all the way from my US boarding airport to ITM... it is in the same ticket, so I am hoping that!).

Thanks.