[mookiemookie]

1. Yup. Blurry scopes are a sure sign of the SH3 Commander malfunction feature at work. Others include not being able to reach top speed even at ahead flank, and battery life that is noticeably shorter

2 & 3. Sadly, neither one of these alert destroyers to your presence. Test it for yourself in a single mission sometime. You can ping away to your hearts content and the DD's will happily sail along, none the wiser. It feels like cheating to me, so I don't do this in game.

4. The coal tenders next to the lightships are placed there so your watch crew will spot the lightships themselves. A limitation of the SH3 engine prevents stationary ships from staying stationary, and so in order to make lightships stay where they are, they have to be scripted as a unit type that isn't detectable. Anyways, it sounds like you got a lucky crit hit on the coal tender.