I'll have a go at answering Q1, 3 & 4:
1. The towed array is the most effective passive sonar device that your submarine has. To avoid losing it in a combat situation it might be worthwhile considering only deploying half of it or less so that you can retrieve it more quickly should you need to do so. However, doing this will reduce it's overall effectiveness.
3. I don't think you can.
4. No, torpedo depth is preset at launch, you can only steer the torpedo using wire guidance.
Nemo
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"I'm afraid there is no disguising the fact that King's obsession with the Pacific and the Battle of Washington cost us dear in the Battle of the Atlantic".
Sir John Slessor GCB, DSO, MC, DL
AOC-in-C Coastal Command RAF
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