Is it some how better to thaw out meat in a refrigerator versus on the counter versus running hot water over it versus in the microwave? Is it the longer the time meat has to thaw out the more taste is retained? If I'm pressed for time, could combinations be used: for example leaving meat on the counter for 1 hour and then microwaving it until completed thawed?
I would think that USDA would err on the side of conservative when it comes to safety, especially with no financial interests in the equation
Perishable foods should never be thawed on the counter, or in hot water and must not be left at room temperature for more than two hours.
Even though the center of the package may still be frozen as it thaws on the counter, the outer layer of the food could be in the "Danger Zone," between 40 and 140 °F — temperatures where bacteria multiply rapidly.
When thawing frozen food, it's best to plan ahead and thaw in the refrigerator where it will remain at a safe, constant temperature — at 40 °F or below.
There are three safe ways to thaw food: in the refrigerator, in cold water, and in the microwave.
They're all covered in the above link, but here's the fastest one since it best meets your requirement of reasonably quick results:
When thawing food in a microwave, plan to cook it immediately after thawing because some areas of the food may become warm and begin to cook during the thawing process (bringing the food to "Danger Zone" temperatures). Holding partially cooked food is not recommended because any bacteria present wouldn't have been destroyed and, indeed, the food may have reached optimal temperatures for bacteria to grow.
After thawing in the microwave, always cook immediately after, whether microwave cooking, by conventional oven, or grilling.
Foods thawed in the microwave should be cooked before refreezing.
And when all else fails:
Cooking without thawing
When there is not enough time to thaw frozen foods, or you're simply in a hurry, just remember: it is safe to cook foods from the frozen state. The cooking will take approximately 50% longer than the recommended time for fully thawed or fresh meat and poultry.
From personal experience, I prefer the cold water method to microwave for fast thawing, but I rarely if ever use a microwave anyway so others on here might have techniques that minimize the flavor/quality downside of it.
The factors that make the microwave method less safe are what also lower the quality, taste and texture of the food – the unevenly thawed parts, over-cooking some of it while undercooking other areas, etc.