Though the query seems messy it will do the trick.

create table myTable(ACTID int, TRID int, CD int, DATE varchar(5))
insert into myTable values( 1,    1,     0, '12/04');-- - To be deleted 
 insert into myTable values(1,    2,     2, '11/04');-- - To be deleted 
 insert into myTable values(1,    3,     4, '10/04');-- - Do not delete 
 insert into myTable values(2,    4,     0, '10/04');-- - To be deleted 
 insert into myTable values(2,    5,     2, '11/04');-- - Do not delete 
 insert into myTable values(3,    6,     4, '12/04');-- - Do not delete 
 insert into myTable values(3,    7,     4, '11/04');-- - To be deleted

Delete Query:

delete a from myTable a inner join myTable b 
  on (a.ACTID=b.ACTID and b.CD=4 and a.CD<4)
  or (a.ACTID=b.ACTID and b.CD=4 and a.TRID<>b.TRID and (a.CD=4 and b.CD=4) and a.DATE<b.DATE)
  or (a.ACTID=b.ACTID and b.CD=4 and a.TRID<>b.TRID  and((a.CD = 0 and b.CD =2)or(a.CD = 2 and b.CD =0)) and a.DATE<b.DATE)
  or (a.ACTID=b.ACTID and a.TRID<>b.TRID  and(a.CD in (0,2) and b.CD in (0,2)) and a.DATE<b.DATE)
    and not exists (select * from mytable m where m.ACTID=a.ACTID and m.CD=4)

select * from myTable

fiddle

Here's my try:

CREATE TABLE #t(ACTID int, TRID int, CD int, DATE varchar(5))
INSERT INTO #t VALUES(1, 1, 0, '12/04')-- - To be deleted 
,(1, 2, 2, '11/04')-- - To be deleted 
,(1, 3, 4, '10/04')-- - Do not delete 
,(2, 4, 0, '10/04')-- - To be deleted 
,(2, 5, 2, '11/04')-- - Do not delete 
,(3, 6, 4, '12/04')-- - Do not delete 
,(3, 7, 4, '11/04');-- - To be deleted 
 
SELECT  *
FROM    #t t
WHERE   EXISTS(
        SELECT  1
        FROM    #t t2
        WHERE   t2.ACTID = t.actid
        AND (
            (t.cd <> 4 AND t2.cd = 4)
        OR  (t.cd = 4 AND t2.cd = 4 AND t2.DATE > t.date)
        OR  (t.cd <> 4 AND t2.cd <> 4 AND t2.DATE > t.date)
        )
    )

It returns list of ids to remove by filtering out:

1. Those with CD <> 4 where exists a CD=4 row
2. Where exists another CD=4 row with later date
3. Those non CD=4 rows with lower dates than other non CD=4