To answer your question -
1. Trial expires after 30 days.
2. Updates can be applied using RUM. please download RUM from - http://labs.adobe.com/downloads/aameetools.html
its documentation is available here - http://labsdownload.adobe.com/pub/labs/aameetools/aameetools_rum_docs.pdf
If you want roll out image where you have deployed Master collection, then install a trial package on one machine, creates its image and roll out image to other machines. Then run AdobeSerialization executable on all machines to serialize it.
Rahul | firstname.lastname@example.org | Adobe Systems
RUM will run irrespective of license/no license on machine, but all the available updates might not be applied. Reason - there are different category of updates, some of which need valid license to be present on machine. So only those updates which dont need valid license will be applied - in trial expired scenario. Ideally valid license should be present on machine while updates are being deployed.