My non-expert take on this:
Q1 - HMS Cornwall - the external bulges make it a Type 1 County, the presence of a hanger in 1937 and the lack of a cut down stern point to Cornwall rather than any of the others.
Q2 - Agree with Jim, its HMS Hermes
Q3 - Agree this is a Cavendish (or Hawkins) class cruiser but think it is probably Vindictive, which was a training cruiser at the time, but could also be Frobisher (also a training cruiser up to 1937). Doubt if it would be Hawkins, as she was in Portsmouth reserve at the time.
Q4 - No idea what the fuzzy ship is.
Edit: On blowing it up as much as possible, ship appears to have three funnels, so I suspect it is Cornwall again
Q5 - Can't see enough of the depot ship to identify her.
Destroyer appears to be an Admiralty Large Leader class(it has two apparently round funnels, a midships gun on a bandstand and small gun shields that don't reach the deck)
Inboard submarine looks like a minelaying submarine of the Grampus class, probably Narwhal, as the other two that were in commission at the time (Grampus and Rorqual) were in China at the time.
Outboard sumbarine looks like a Group 1 S class (Swordfish class) (later Groups of the S class (Shark and following types) had a longer projection forwards from the base of the conning tower).