Object: OpportunityLineItemSchedule. When users edit and change schedule amounts.

I'm needing some guidance on a solution for the following:

When product revenue schedules move from one quarter to another: I.E. - 1/7/2018 = 10,000 and $5000 moves to 4/7/2018

Finance wants to report on - When it moved. How much moved. What quarter it moved from. What quarter it moved to. Who moved it. Did Total Budget Move. If so, how much?

I have searched around and it seems as though OpporunityLineItemSchedule has a lot of limitations.

Does anyone have a good solution to be able to report on this data? A custom object with APEX writing back to Object?

Thanks

Our company is faced with the following problem:

Users enter in data on a platform and our BI team uses Google Big Query. They then send us a file to load into SFDC. I'm trying to find a solution for Google Big Query to write back to SFDC but all I find is SFDC-->GBQ.  Or how to integrate the platfrom to SFDC and then have the BI team extract from SFDC?

Does anyone have any ideas how to solve? 

Ask: As a Sales Manager I would like to limit users ability to create tasks if an Opportunity has been closed for more than 4 days. 
As an Admin a Validation Rule doesn't seem like a viable solution. Trying to create a Trigger but running into some issues.

Problem - Line 5 - Inequality Operator not allowed for this type: Object
IF (a.WhatId!=null && String.valueOf(a.WhatId).startsWith('006')&& a.What.get('CloseDate') < (System.today()- 4) &&(RoleId =='00E800000029UCT'))
Trying to look at opp close date and evaluate if 4 days has past. If so, want to restrict ability to create tasks for certain role. 
Could someone help? Of if there is a better solution?

Trigger:
trigger NoTaskCreationForSE on Task (before insert) {
    String RoleId = UserInfo.getUserRoleId();
    for (Task a : Trigger.new)    
        
    IF (a.WhatId!=null && String.valueOf(a.WhatId).startsWith('006')&& a.What.get('CloseDate') < (System.today()- 4) &&(RoleId =='00E800000029UCT'))
        
    {
        a.addError('You Cannot Add Tasks Once An Opp Has Been Closed For More Than 4 Days');
    }
        
}

 

Ask: As a Sales Manager I would like to limit users ability to create tasks if an Opportunity has been closed for more than 4 days. 
As an Admin a Validation Rule doesn't seem like a viable solution. Trying to create a Trigger but running into some issues.

Problem - Line 5 - Inequality Operator not allowed for this type: Object
IF (a.WhatId!=null && String.valueOf(a.WhatId).startsWith('006')&& a.What.get('CloseDate') < (System.today()- 4) &&(RoleId =='00E800000029UCT'))
Trying to look at opp close date and evaluate if 4 days has past. If so, want to restrict ability to create tasks for certain role. 
Could someone help? Of if there is a better solution?

Trigger:
trigger NoTaskCreationForSE on Task (before insert) {
    String RoleId = UserInfo.getUserRoleId();
    for (Task a : Trigger.new)    
        
    IF (a.WhatId!=null && String.valueOf(a.WhatId).startsWith('006')&& a.What.get('CloseDate') < (System.today()- 4) &&(RoleId =='00E800000029UCT'))
        
    {
        a.addError('You Cannot Add Tasks Once An Opp Has Been Closed For More Than 4 Days');
    }
        
}