Yes, as posted above...a lot of the "chinese" flavour comes from the wok it's self. But it is not just the wok...
Here in the great land of Aus, Chinese cooks (many of them anyway) actually call wok cooking "wokking". I have seen many actually cook their own dinner before they start wokking. It's not because they are hungry, it's because the wok is "fresh". They will cook thier own dinner using strong flavoured things like garlic, salt fish etc. Then when it comes time to start wokking for customers the wok is "seasoned" already.
You can get a similar effect at home. Cook each ingredient seperately and for a very short time (10 or 15 seconds). Then leave each on a plate until you are ready to finish. Each ingredient will leave it's own hint of flavour in the wok. Then later, when you are ready heat the wok to almost red hot and the flavours will turn into the wok hei mentioned above.
I use one of those portable single burner camp stoves for my wokking. It takes a disposable 220 gram gas can...Do you know the type I mean, or would you like me to post a photo? Using one of those means I can simply take it out side where the smoke and smells don't matter.
The other thing you ask about is "secret" ingredients...You bet ya! They sure do have little secrets. Your sherry is one of them. Of course you can use rice wine also. Even if a recipe does not call for it, many stir frys are improved with a small splash of rice wine or sherry.
Try this...Instead of marinating or tenderizing your meat in a white-wash (corn flour and water). Make the same type of corn flour mix using sherry or rice wine instead of water.
There are lots of "secrets" with Chinese cooking. Way to many for me to rattle off...Even if I did know them all, which I don't. One of my favorites is coffee! Use instant coffee powder. A tea spoon in Mongolian lamb makes all the difference. A small sprinkle in black bean beef works wonders!
Maybe other people can post some more "secrets".
Hope that is of help.