That looks like a very interesting itinerary - out of your stops we have only been to Copenhagen, Dublin, Orkney, and Lerwick.
Your itinerary looks to be more about landscapes and small villages rather than wildlife per se. I agree that you'll see lots of birds. The Neolithic sites on both Orkney and the Shetlands are interesting to visit as well. We did a DIY tour via rental car on Orkney which made for a very enjoyable day.
Weather is always unpredictable from year to year but I would not expect it to feel like a warm summer. You'll get lots of daylight but cloud cover, wind, and exposure to the North Atlantic may all combine in varying degrees to make it chilly at times. If I were packing for this itinerary I'd probably bring a pair of shorts, more long pants, and plenty of layers. I'd expect to need a light jacket more days than not.
I just looked at my photos from Orkney in August 2014, and despite relatively sunny skies we were both wearing long pants and a light jacket. June is not likely to be warmer than that.
Depending on the wind direction, though, your balcony could be very pleasant. The best combination would be a clear day when the sun is shining on your balcony, and the wind is hitting the other side of the ship so you're sheltered on the leeward side.
Have a great trip, and make sure you post some pictures!