PMD Issues in Code - Are they critical?

PMD Issues in Code - Are they critical?

We have a number of issues that PMD has identified for us - a lot of which
seems nit picky. I have a list below - may I ask the hive mind - if you
had to pick the top 5 crticial rules out of below list what would they be?
I am trying to balance effort with criticality of what would be bad if it
made to production.
Thanks in advance!
AssignmentInOperand
AvoidDeeplyNestedIfStmts
AvoidDuplicateLiterals
AvoidInstantiatingObjectsInLoops
ClassWithOnlyPrivateConstructorsShouldBeFinal
CollapsibleIfStatements
CyclomaticComplexity
EmptyIfStmt
ExcessiveMethodLength
ExcessivePublicCount
ImmutableField
InefficientStringBuffering
InsufficientStringBufferDeclaration
LocalVariableCouldBeFinal
LooseCoupling
MethodArgumentCouldBeFinal
NcssMethodCount
NPathComplexity
PackageCase
PositionLiteralsFirstInComparisons
SignatureDeclareThrowsException
SingularField
TooManyFields
UncommentedEmptyConstructor
UncommentedEmptyMethod
UnusedImports
UnusedPrivateField
UseSingleton