Ne’er-do-wells have ways of getting round a bloomer (7)

'ne'er-do-wells' is the definition.
The answer and definition can be both people as well as being plural nouns.
Maybe there's an association between them I don't understand?

'ways of getting round a bloomer' is the wordplay.
'ways of getting' becomes 'ws' (I can't explain this - if you can you should give a lot more credence to this answer).
'round' means one lot of letters goes inside another.
'a bloomer' becomes 'aster' (aster is a kind of flowering plant).
'ws' going around 'aster' is 'WASTERS'.

'have' is the link.

Can you help me to learn more?