I need to create a report which shows Approval history (App level 1/2/3) on case object. I created report on Process Instance and show case number(using Record Name field) but that didn't solve the purpose as I cannot see the approval levels (1/2/3)

Requirement: When certain profile and role users select No to a picklist value, they should get an error saying not allowed

I tried below and got syntex error. Is it the correct formula?

AND
(
 ISPICKVAL( Accountable__c , "no") ,
AND
(
 $User.Id  = "00e800000014wve"
OR
(
 $User.UserRoleId  = "00E34000001pYNH",
))

I need to create field for custom object and the field type requirement is Number with floating-point decimal. How to do that? Should I select data type Number with 2 decimal ?   
Field Type: Number with floating-point decimal  

I have a workflow that updates the status of parent case (pick list) when sub case is updated. I need to update the parent case when sub case got cancelled. Do I have to do it with process builder?
Not able to find way to update existing workflow.
Rule Criteria :(Case: Sub case updatedequalsTrue)
Immediate Workflow Actions : TypeDescription Field Update : Change Status to processing

Requirement: When certain profile and role users select No to a picklist value, they should get an error saying not allowed

I tried below and got syntex error. Is it the correct formula?

AND
(
 ISPICKVAL( Accountable__c , "no") ,
AND
(
 $User.Id  = "00e800000014wve"
OR
(
 $User.UserRoleId  = "00E34000001pYNH",
))

I have a workflow that updates the status of parent case (pick list) when sub case is updated. I need to update the parent case when sub case got cancelled. Do I have to do it with process builder?
Not able to find way to update existing workflow.
Rule Criteria :(Case: Sub case updatedequalsTrue)
Immediate Workflow Actions : TypeDescription Field Update : Change Status to processing