12A : Bearberry (3-4) : U?A - ?R?I
15A : Lacking front teeth (8) : ?D?N???E
48A : Pseudonym adopted by Addison for many of his papers in the Spectator (4) : ?L?O
3D : Follower of the doctrine of the nominalist schoolman who died c.1349 (8) : ?C???I?T; Is it OCKAMIST (without the ‘H’)?
9D : Relating to manual workers (4-6) : ?D?E – ?O?L?R Is it IDLE TOILER or EDGE TOILER?
Many thanks
Lie-In King : thanks for "Blue Collar" - but then that means 13A : A grim, threatening appearance (4) is L?U? : can't see that such as LOUD fits with the definition?