Error: Invalid Data. 
Review all error messages below to correct your data.
Apex trigger EscalateCase caused an unexpected exception, contact your administrator: EscalateCase: execution of BeforeInsert caused by: System.QueryException: Non-selective query against large object type (more than 100000 rows). Consider an indexed filter or contact salesforce.com about custom indexing. Even if a field is indexed a filter might still not be selective when: 1. The filter value includes null (for instance binding with a list that contains null) 2. Data skew exists whereby the number of matching rows is very large (for instance, filtering for a particular foreign key value that occurs many times): Trigger.EscalateCase: line 76, column 1

It is erroring on line:

List<Case> cCaseTypes = [SELECT Status, Id FROM Case where Status='Escalation Hold' AND ParentId =:escalatedcase.id LIMIT 10];

trigger EscalateCase on Case (before update, before insert) {
//MAP record type ID's to record type names.
        List<RecordType> rTypes = [select id,name from RecordType where SobjectType='Case'];    //pull recordtype Id's and record type names from recordtypes where the sobject is contract
           
        MAP<Id , String> maprtID_rtName = new MAP<ID , String>();  //map record type ID's to record type names.
        for(RecordType rTypeObj :  rTypes)
        {
            maprtID_rtName.put(rTypeObj.id , rTypeObj.Name); //for all recordtypes... log id's and record type names.
        }
//MAP Record type names to record type ID's
        List<RecordType> rTypesCases = [select name,id from RecordType where SobjectType='Case'];    //pull recordtype Id's and record type names from recordtypes where the sobject is contract
        
        MAP<String, ID> maprtName_rtIDCases = new MAP<String, ID>();  //map record type ID's to record type names.
        for(RecordType rTypeObj :  rTypesCases)
        {
            maprtName_rtIDCases.put(rTypeObj.Name, rTypeObj.id); //for all recordtypes... log id's and record type names.
        }
        
//MAP Case User Owner/Queue Names to reference ID's
        List<User> uTypesUsers = [select name,id from User];    //pull recordtype Id's and record type names from recordtypes where the sobject is contract
        
        MAP<String, ID> maprtName_rtIDUsers = new MAP<String, ID>();  //map record type ID's to record type names.
        for(User uTypeObj :  uTypesUsers)
        {
            maprtName_rtIDUsers.put(uTypeObj.Name, uTypeObj.id); //for all recordtypes... log id's and record type names.
        }
        
//MAP Case Group Owner/Queue Names to reference ID's
        List<Group> gTypesGroups = [select name,id from Group where Type='Queue'];    //pull recordtype Id's and record type names from recordtypes where the sobject is contract
        
        MAP<String, ID> maprtName_rtIDGroups = new MAP<String, ID>();  //map record type ID's to record type names.
        for(Group gTypeObj :  gTypesGroups)
        {
            maprtName_rtIDGroups.put(gTypeObj.Name, gTypeObj.id); //for all recordtypes... log id's and record type names.
        }
    
////map for temporary return from escalation
    
    

//bulk cases for upsert
      List<Case> Cases = new List<Case>();
      List<CaseComment> ccomments = new List<CaseComment>();
      List<CaseComment> dcomments = new List<CaseComment>();
      List<CaseComment> pcomments = new List<CaseComment>();
      boolean escalated = false;
      boolean bccomments = false;
      boolean bdcomments = false;
      boolean bpcomments = false;
      MAP<ID, ID> mapescalate_add = new MAP<ID, ID>();

//lets have a look at all the trigger(s)
for (Case escalatedcase:Trigger.new){

escalated = false;    
    
//trying to close the parent case while children are still open   
      if (escalatedcase.Status=='Closed') { //trying to close the parent case while children are still open
            integer close = [Select count() from Case where ParentId = :escalatedcase.id and isClosed != true];
            if (close > 0) {
                  escalatedcase.addError('There are still Child Cases Open - Please close and try again!'); //in your face!
            }
      }
//END trying to close the parent case while children are still open


      if(maprtID_rtName.get(escalatedcase.RecordTypeId) == 'National Client Service') {
            
                  if(escalatedcase.ParentId == null) {
                      
                        if(escalatedcase.Status != 'Escalated' && escalatedcase.Status != 'Returned from Escalation' && escalatedcase.Status != 'Closed') {
                              //if any escalatedcase childcase has a status 'Escalation Hold' then pass the comments back to that case and put this case on status escalated and put that status as new
                              // then if not, proceed with the escalation group stuff
                            
                            //List<Case> cCaseTypes = [SELECT Status, Id FROM Case where ParentId =:escalatedcase.id LIMIT 10];
                            List<Case> cCaseTypes = [SELECT Status, Id FROM Case where Status='Escalation Hold' AND ParentId =:escalatedcase.id LIMIT 10];
                            for(Case eCase : cCaseTypes) {
                                If (eCase.Status == 'Escalation Hold') {
                                                
                                      Case CaseAdd = new Case(Id = eCase.id);
                                      CaseAdd.Status = 'New';
                                      CaseAdd.Escalation_Completion_Date__c = System.now();
                                      Cases.add(CaseAdd);
                                    
                                    
                                            List<CaseComment> comments = [Select c.Id, c.ParentId, c.IsPublished, c.CommentBody, c.CreatedById, c.CreatedDate, c.SystemModstamp, c.LastModifiedDate, c.LastModifiedById, c.IsDeleted from CaseComment c where c.ParentId = :escalatedcase.Id];
            
                                            for(CaseComment oldcomment :  comments) {
                                                CaseComment newcomment = new CaseComment();
                                                dcomments.add(oldcomment);
                                                bdcomments = true;
                                                newcomment.ParentId = escalatedcase.ParentId;
                                                newcomment.IsPublished = oldcomment.IsPublished;
                                                newcomment.CommentBody = oldcomment.CommentBody + escalatedcase.OwnerId + escalatedcase.Owner.Name;
                                                //Do I want to remove duplicates?
                                                //if (newcomment.CommentBody.substring(0,6) == 'Parent') { } else {
                                                    pcomments.add(newcomment);  
                                                    bpcomments = true;
                                                //}
                                            }
             
                                        
                                        
                                        escalated = true;
                                }
                            }