We sympathize with your deer browsing issues, as it is a persistent and important problem region-wide. Repellent sprays tend to share a common palette of ingredients across brands, which are usually a combination of taste and smell deterrents. [The main mouth-irritant components are either hot pepper extract (capsaicin) or black pepper.] Unless the spray saturates flowers, it's unlikely the pollinators will be exposed enough to deter their visits. That said, we do not have study data available on what effect they may have on foliar feeding of insects, such as butterfly larvae (caterpillars), or beneficial insects hunting prey (some of which also visit flowers). Plants do give off their own suites of chemical odors these insects can detect - including odors specific to when they are damaged by pests, which help "call in" beneficials for pest control - so if the repellents don't mask this too much, they may not interfere with insect visits overall. Unfortunately, the only recourse to using only the limited range of very deer-unpalatable plants or regularly spraying with repellent is to physically block access by using deer fencing.

Spraying repellent around the garden perimeter only might work, but isn't reliable. A lot depends on how desperate the deer are and how strongly they've developed their habitual foraging patterns; you may have to experiment and see what happens. Deer have been known to walk through plants they aren't interested in eating (such as those with strong foliage scents, or sharp-leaved tall grasses) to get to those they will eat, so one could expect that repellent used on some plants may make them reluctant to browse there but not necessarily motivated to shun the entire area. Usually, spraying the individual plants at risk, which you have been doing, is the recommended approach. In this way, they learn to associate the repulsive experience with that particular plant or location.

Birds probably won't be repulsed by the sprays. (The fact that there aren't widely-available repellent sprays for keeping birds away from, for instance, cherry and blueberry crops, suggests this holds true.) Birds don't taste (or aren't bothered by) capsaicin, which is one reason it's added to some suet blends and other wild bird foods to deter squirrels from stealing it. In either case, it's likely the only direct exposure birds might have to deer repellent would be if the spray covered plant seed heads or berries and hadn't yet weathered off.

Miri