all the answers are physical beings

[altivo]

would be very grateful if anyone can help
madly dashing away with a smoothing iron is a fruitless exercise 4-5 5
dublin clergy man who made silver gulls avert disaster 4,5
bird to pick off by rifle fire 5
traitor hunting wildly for the sage's snark 5,2,3,5

[johnalex]

4. Snake in the Grass

[emeritus]

3 Silver gulls avert is an Anag of Gullivers Travels written by Jonathan Swift a Dublin Clergyman ???

[johnalex]

4. . . . just to clarify, sage's snark is anagram of grass snake

3. Snipe

[Jumbuck]

1 wild-goose chase (a goose is a tailor's iron)

[writesbad]

Jonathan Swift is also known as Dean Swift

[altivo]

many thanks