Newbie questions, production questions

I’ve downloaded the trial version does this differ in any way to the latest enterprise release ?

Can the Enterprise workflows be run on the open source version ?

We would like to have multiple environments but by having a separate flowable install for Dev/UAT/Mirror and prod for example, how would licensing work, would we need a licence for each environment or would you allow us to just pay for production.

Under flowable server documentation it suggests 100/1000GB for disk (file persistence) what is the purpose for this storage space, how do you make this HA, or am I mixing this up with the database ?

Flowable enterprise security what does it contain X-Pack ?