Rangy quality of relations in alleys start slowly (9)

'rangy quality' is the definition.
(I know this)

'relations in alleys start slowly' is the wordplay.
'relations' becomes 'kin' (both can mean one's family).
'in' means one lot of letters goes inside another.
'alleys' becomes 'lanes' (I can't justify this - if you can you should give a lot more credence to this answer).
'start' suggests taking the first letters.
The initial letter of 'slowly' is 's'.
'kin' placed within 'lanes' is 'lankines'.
'lankines'+'s'='LANKINESS'

'of' is the link.

Can you help me to learn more?