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Are you sure you've identified these creatures correctly? Other than crane flies, which resemble mosquitos on steroids, flies generally are not a problem on PNW lawns. Could these possibly be small moths that you see flying around? Lawn moths, the adults of the sod webworm, are very common now and are small, whitish gray insects. That late day flying pattern is an egg laying process and the larval webworms can indeed cause die out and brown patches in late summer, specially in full sun locations. Here is a link that might be useful: sod webworms

Is it the window panes rattling within the sashes, or (more likely) the window sashes themselves rattling against the frames? The former might be helped by reglazing (and you will actually see gap between the glass and the sash if you rattle it yourself), but I'd guess it's the latter, since that's super common in older houses. You can add insulation to the windows and win on two fronts: less rattling and fewer drafts. We used spring bronze weatherstripping on ours but there are lots of options, some simpler to install than others depending on your windows. The weatherstripping isn't visible from the outside but helps the window sit more securely in the frame. Should decrease rattling substantially.

QuietWalk makes different products for different situations. If you are on gypcrete that suggests an apartment building or wood substrate with gypcrete topping. Normally you do not need a vapour barrier over it. QuietWalk produces a product WITH a vapour barrier attached and one WITHOUT. You will need to tell us a bit more about your situation. And here is the required 'flatness rating' for your floors: "Make sure the subfloor is flat. Any unevenness greater than 1/16-inch over the length of 40 inches must be smoothed out." That's 1.5mm over 1m. That is not very flat. Traditionally most laminates using the Uniclic system require 3mm over 3m. Your floor allows 4.5mm over 3 meters. I'm wondering if there is too much bounce/play with these floors. Gypcrete is NOTORIOUS for being HORRIBLE to deal with. If your costs for subfloor work were too low, the installers may have skipped a few steps just to keep from losing too much money. But first things first: which QuietWalk do you have?