Just got your message, and am reading through the advice you received. The good news is that August is not terribly buggy, and this has been a low bug year so far anyway! August could be rainy, so rain gear is good advice; plan on dressing in layers, and avoiding cotton clothing as much as possible.
There are lots of hiking options, if you have a specific itinerary, I could probably give you some ideas. A few areas to consider visiting close to Anchorage…Arctic Valley (may have blueberries in August), Hatchers Pass (check out Independence Mine), Eagle River Nature Center (hike on some of their trails), Girdwood (find the Winner Creek trail behind Alyeska Hotel, or if you are feeling ambitious, the trail to Raven Glacier is SPECTACULAR, and is the first part of the famous Crow Pass trail. You can also ride a lift up Mt Alyeska, and there’s a restaurant up there. The Double Musky is a nice, nationally known restaurant in Girdwood too.) Portage is not far from Girdwood, and the short trail to the Byron Glacier is nice. There’s also a salmon viewing area that will probably be active then.
Talkeetna is a fun place to go, and you might enjoy a visit to Matanuska Glacier, if you want actual glacier contact. There’s a zipline somewhere around Talkeetna, I think. Try Googling for that.
I would strongly suggest a drive to the Kenai Peninsula. Consider going to Homer, abt a 5 hour drive, and worth the trip. It may not be too hard to get a hotel or B&B res for August, even this late. The tours here are worth doing, and will get you across the bay. Try to arrange something during a minus tide for cool tidepooling: http://www.akcoastalstudies.org/guided-tours/book-a-tour-or-a-program.html Or go to Seward, and check out Miller’s Landing for kayak rentals. See if you can book a guided kayak tour. They have boats in Seward that will take you fishing or wildlife viewing in Kenai Fjords Nat Park. Check out the Seward Sealife Center. I love the Harding Icefield hike at Exit Glacier just outside Seward.
And there’s Denali. Denali can be a bit of an undertaking, as you can’t drive in very far, so there are buses to book and such. May not be too hard in August. You CAN drive in about 15 miles, and there are hikes to be done even in that short distance.
Northern Lights…well, maybe. But I wouldn’t count on that. 