1) never had a problem with mines... you have a map where the minefields and anti-Uboat-nets are at the ports and the Strait of Dover is covered ith anti-Uboat-Mines till GWX tells you it is sve to pass through.
Well other than that I have no clue where mines could be... I also have never passed the strait of dover dived but if I thought I have to ... I did it at night and very carefully
There is a paragraph in the GWX-Manual about mines and what to do if you ran into one.
about 2)
Yes I have experienced this as well and honestly I do not make a big thing about it... I have a very good sonar officer and let him do the spotting...
And Welcome to the board!