The answer to #2 is NO. You can not use a second hand SKREEM module. It is Vin specific. Needswings.com is going to be the best option if you find yourself in need of this unit.
#1 is a viable option, proceeding with the way you mentioned. If you do want to get a second key (peace of mind), again Needswings has, prompt, reliable an good turn around time ,on this issue.