OWZ
The 2 conspicuities are of course however “known traffic” when you can assure yourself that you really do know the intentions.
Known, but not identified = unknown
OWZ I would say
Q1- No
Spitoon --Of course, there's nowt to stop you identifying it with a turn (subject to all the usual cautions)
I refer my honourable gentleman to Mats Pt 1
Section 1 Chapter 5 Page 6
4.1 Controllers should use Mode A to identify aircraft whenever suitable equipment is available. One of the following methods is to be employed
etc etc
OWZ
Q2 Mats pt1 sect 1 ch 5 page 1
The act of identifying an aircraft does not imply that a service is being given.
Q3 I concur with Spitoon 
How sad is this 
just had a look at the AIP some examples of SSR allocations outside CAS
GP 7+1
BE 6+2
NR 7
MH 15
TE 24
CN 14
NH 14
(Not checked too much for accuracy)
Does vary why not ask for more if you feel you can justify the need?