SA, or what looks like SA at nap time can be UT, that's what I found with my DS anyway and have seen on several threads. Although LO might calm and go to sleep with a hand on him at an earlier time, if the nap is moved later there is often a reduction in the SA symptoms. Obviously SA can be for other reasons too and can be very apparent during A times, I'm just mentioning what I've found with the SA around naps.
I think if you keep that nap at the later time (I think you are at 12pm, you might move it later, even "set" naps can be moved when needed to establish the most suitable routine) you might see a reduction in SA.
Another reason for SA is of course OT and LO just being a grouch from not having enough sleep. IMO the later nap can lead to a better nap and can also reduce afternoon OT signs or at least reduce the A time to BT which helps to avoid OT during this transition.
For SA during A time I found the best routine through was to take him everywhere with me, talk to him about everything I was doing and tell him if I was leaving the room, invite him to come with me, or tell him I'd be back eg "I am just getting my drink from the kitchen, I'll be back". When I returned to the room I'd say "I'm back" - I found these key phrases very useful as he grew up and he seemed to have a lot of confidence and trust in them.
WD - hmm..sorry but I'm going to say the same thing again. The later nap time can really help with WD. What can appear to be a need for a long WD can really be LO being unable to settle well for the nap due to a touch of UT. I found for most phases when mine was super tired he slept well, any slight UT caused big problems for us (including waking too early from the nap and being a huge grouch all afternoon). Mine liked a very short WD or he felt he was missing out on the day. Upstairs, wee/nappy on, into bed room , one song with cuddle and into bed, kiss and walk out.
Hope you have a good day x