Hi Peter. I recommend that you look at the site map shown at https://www.bcmarinetrails.org/ There you will find some answers.
3. BC ferries has no service to Miner’s Bay on Mayne I. Last year I launched my kayak from the beach at Sturdies Bay on Galiano I to reach Mayne Eco Camping, where I presume you are staying. Alternatively you would need to take a car by ferry to Village Bay and drive to that campsite.
1. There is no camping permitted by Parks Canada at Winter Cove (although there is plenty of room). The best alternative is to paddle to Cabbage I. Be aware of v strong currents and possible boat traffic in Boat Passage.
Narvaez Bay on Saturna or Beaumont on S Pender would be your second night options. There is plenty of current – be aware of it – but mostly less so than in the San Juans. These sites will likely be full every night in August and take no reservations.
2. Mandatory safety equipment depends on length (re flares). You can download the guide here at the Office of Boating Safety site http://www.tc.gc.ca/eng/marinesafety/debs-obs-menu-1362.htm
They have (or had) a separate brocuhure about kayaking safety, too.
Enjoy and maybe even consider joining our club!