Remedy vs ServiceNow

Hello,

Our company made a transition from Remedy to ServiceNow.  There are a couple of things that I would like clarification on.  The transition team is new and I don't believe they're SME with SNOW.  

1. We use cases.  Why is it so hard to update tickets once they're in RESOLVED state?  In Remedy, I can easily update a ticket in any status.  With SNOW, if the STATE is in RESOLVED, I must first change the STATE, the submitter will get a notification, make my updates, and change it back to RESOLVED.   The fields are grayed out when is in RESOLVED state.  Is there a way to bypass that to easily update tickets?

2.  How do you do bulk updates tickets?  For example, if you want to update the category for a group of tickets.

3. I was told that after 2 weeks the RESOLVED case would no longer be able to update.  Is that accurate?  We often get updates from our customers months after we create a ticket so I don't know how this will work out.