No, they don't need to be covered.
All suggestive tattoos need to be covered during work hours but you can wear them with pride in your own time
As long as the tattoo does not have the potential to cause offense it is usually not a problem. Certain contracts may differ so i would mention at interview.
Not an issue as far as I was aware.
No suggestive tattoos are allowed on face
Serco (to my knowledge) has no tattoo policy.
No you could have them showing
No the dont
No specific policy