Hi Himalaya,
Having a look at some of the driving times and things you (will) want to see, how about the following more balanced itinerary:
Day 1 Flight to Keflavik, sea birds at Gardur lighthouse [10 min], drive to southern Snaefellsnes [2.5-3 h] with some birding along the way in Myrar (endemic wader subsp., ducks, Red-throated Diver). I'd suggest somewhere like Arnarstapi, cause you can do an evening visit to the cliffs to see the auks there, then nip around the peninsula in the morning to Stykkisholmur for the boat trip at 11 a.m.
Day 2 Snaefellsnes peninsula drive in the morning [2-2.5 h with stops], Breidafjordur excursion at 11 a.m. (
www.seatours.is - look for White-tailed Eagle on this one), drive to Akureyri [5 h]. Again you don't need to be in Husavik early and Akureyri is a lovely little town.
Day 3 Drive to Husavik with optional stops at Vaglaskogur (forest birds) and Godafoss waterfall [2 h], whale excursion (
www.northsailing.is), short drive to Myvatn [45 min], Myvatn area rest of the day, Myvatn spa to rest your weary legs :t:.
Day 4 Myvatn area in the morning (birds or amazing volcanic sites, it's up to you), long drive to Hofn [6 h] - great scenery though.
day 5 Morning drive from Hofn to Skaftafell [2 h] with stop at Jokulsarlon glacial lagoon (skua's & Harlequin Ducks) and walk in Skaftafell NP, afternoon drive to Hvolsvollur/Hella [5 h] through the sandur & lavafields, with stops at the black beach of Vik (puffins) and the waterfalls at Skogar and Seljalandsfoss.
Day 6 Drive to Gullfoss [1 h], visit the waterfall and Geysir area, drive to Reykjavik [1.5-2 h] with a stop at Thingvellir NP, afternoon in Reykjavik, night on the town B
Day 7 Flight home, visit Blue Lagoon if you have the time.
As you can see doing the full circle involves quite a bit of driving, but you get the full Iceland experience. If that's a bit much, I recommend driving to the Borgarnes area on day 4 (afternoon, about 5 h from Myvatn) and doing the Golden Circle at your leasure on day 5.
Let me know if you need any more info - I've been a tour guide in Iceland for 7 years so know my way around