You've got a great pan and in a short time I'm sure you'll come to love it.
When using a standard pan (one without non-stick coating), heat your pan dry over high heat until you can hold your hand about 6-inches above the cooking surface and feel the heat radiating upward. This allows the tiny cracks and crevices that are imperceptible to the bare hand to expand and when the oil is added, it will coat and create a more even cooking surface.
Add just enough oil to lightly coat the surface. Adding to much oil leads to pan-frying which is fine if you're frying chicken but not what you want when searing and sauteing meat. There should just be a thin film across the bottom of the pan. An additional benefit to first heating the pan is the fact that it will actually take less oil to coat the pan due to the decreased viscosity. When the oil hits the hot pan it will instantly heat and should shimmer across the bottom like water on a freshly cleaned windshield.
You don't put the oil in the pan first because the longer oils and fats heat the quicker they break down and smoke. If you were to add cold oil and cold food to a cold pan and then start heating, you just end up with a big sticky mess.
Make sure you're prepared to add the food to the pan once the oil goes in otherwise the oil will start to burn.
The issue with burning and overcooking is going to be a matter of controlling the heat. Start searing and sauteeing over high heat because as food is added it will suck a good deal of heat from the pan. If it isn't extremely hot to begin with you'll end up with a steaming mess of gray colored meat or vegetables that aren't doing much cooking. Once the meat is browned but needs further cooking you can always turn down the heat to prevent excessive browning and crusting before the interior is done.
Even if you aren't planning to do a pan sauce, or if you've burnt what was cooking in the pan, you'll still want to deglaze with some water while the pan is hot (you can reheat it if it has already cooled down) so that you can scraped up the cooked on bits more easily and have less scrubbing to do when cleaning the pan.
This is quite common and pretty harmless. The scratches you see don't go very deep, nor are they very wide. My All-Clad saute pan is nearing 10 years old and has a ton of micro-scratches on the interior. It still performs beautifully.
That said, the scratches can grab onto proteins and cause sticking. However, this is simple to prevent with both oil and proper pan preheating.
When a pan is preheated properly the metal expands, essentially closing all of the micro-scratches. This prevents the proteins from grabbing onto them and getting stuck. You obviously need oil/fat to assist with this as well.
To properly heat a pan to the appropriate temperature I suggest using the water drop method. If you put a cold pan on heat and drip a drop of water onto it, the water will sit there for several seconds then boil away. As the pan gets warmer this will happen more quickly, fizzling away in a second or so. Once the scratches start to close something weird happens.
First, the drop of water will break into a few mini drops which scoot around the pan as they evaporate. This is a sign that you are almost there. When the drop of water stays whole (mostly) and scoots around the pan like a mercury ball, this is the perfect temperature. I the water instantly vaporizes on contact, you've gone way too far and need to let the pan cool down. At this point you should add your oil/fat, swirl it around, and immediately add your food. (Make sure the mercury ball of water is gone before adding oil).
Also note that the mercury-ball phase is definitely too hot for unclarified butter, and may be too hot for some extra-virgin olive oils. They may instantly smoke upon adding.
Again, it's important to have your oil and ingredients in place (mise en place) before you start. It's quite easy to skyrocket past the mercury-ball phase if you have to open your oil, pour, and then season your ingredients.
Best Answer
This happens to mine, and they are most definitely stainless, not aluminum. Our stainless sink gets the same way. I assume it's from all the minerals in our water. I have found that mixing up some Oxyclean and water and a couple of minutes' soak and a scrub with a plastic scrubber will get rid of it (both from the pan and from the sink). It comes right back, though.
I haven't found that it has any negative impact on the usability of the pans, and doesn't shorten the life significantly if the 14+ year old chef's pan I use almost daily is any indication.
I did a little more research, and it's definitely mineral haze. Recommended treatments are Barkeeper's Friend (mild oxalic acid) soak/scrub, or boiling some vinegar, either one followed by a thorough rinse. In theory, if the haze is left alone it could develop into buildup, which would begin to degrade performance, but in practice it's not an urgent worry.
So if it bugs you, clean it off with mild acid or oxygen bleach. But expect it to come right back. If you only removed it once a year, you'd be a couple of years ahead of my cleaning schedule, and I haven't seen any harm from it.