Some clarifying questions about DLRS

Hi everyone, 

I'm inspecting our rollups and finding some DLRS calculations that I need help understanding a few things.  

My first question is: does a DLRS need to be active in order to run? I'm seeing that all of ours are not active, and the ones that are scheduled do not have a future schedule date. Does this mean they were somehow switched off and I just didn't know about it?  

My second question is: can you run DLRS referencing the fiscal year instead of the calendar year? Things like this fiscal year, last FY, FY 2 years ago…etc. If so, what's the notation for this? 

My third question: is it a problem if the "ID" part of one of the relationship criteria points to a single record in Salesforce? Or is this the notation for the DLRS updating only each single fund with it's respective children? Or something else? Here is the criteria for the DLRS in question, salesforce Id obfuscated with 'singleSFId': 

Amount__c != null 

 AND  

FmlStatus__c in ('Closed','Cancelled','Declined','Executed') 

AND  

FpApprovedDate__c = LAST_N_YEARS:2  

AND 

id = 'singleSFId' 

Thanks for your help,