I do mine pretty snug. I probably pull with 5-10 pounds of uniform tension - about the force which a lifted half gallon to gallon of water pulls on your hand - and initially leave a loose spot at the bottom, lace up, then start re-pulling at the bottom, so the tension goes all the way through. But what is good for me might not be good for you, as everyone has different circulation and boot stiffness. I do it a little looser when I'm not jumping, because there is no safety issue.
In first aid books, they say a wrap is dangerously tight if you loose any sensation. Numb isn't far from the point where cells start to die.
BTW, if the tongue is pretty thin, worn out, or not very well padded, you might be numb from lace bite rather than overall tightness, which can be fixed by doing something to pad or stiffen the tongue. You might also have extra tight spots in your boot that need to be stretched. Cold feet can make you numb too. But no matter what, I would never willingly make myself numb.
I know people who use stiff high level freestyle boots (or hockey boots) so they don't have to be tight. With a boot that is too stiff to flex, the ankle bones have to slide forward and back against the boot as their ankles flex and point (hence they use padding to prevent blisters). If you pulled laces too tight, the ankles couldn't slide, and they couldn't flex or point, which would make skating hard.
I use ice dance boots that are flexible enough to conform to my foot instead. An intermediate stiffness boot is expected to flex a little. In either case, lacing too tight would make the ankle flex almost impossible, so that is a place to stop too. Many coaches tell skaters to lace looser in the middle to allow a flex, and tie overhand knots (perhaps with an extra twist) around the loose area so the reduced tension doesn't spread. I suppose instead of stretching the boot, you could try to create lace loose spots around any place the boot is too tight.
BTW, having space between the skin or sock and the inside of the boot near the ankle bend allows a breakdown crease to form and expand, reducing the boot's lifetime, by about an order of magnitude. There is a clear trade-off between excessive tightness that is bad for you or makes it hard to skate, and boot lifetime. Very, very tight is good for the boot, but not good for you or your skating.
In summary: The goals of snug fit and lacing is to provide your ankles with the support you feel you need to be safe, to prevent blisters and callouses from forming due to slippage against the skin, to prevent any loss of control of the blade, and to slow the breakdown of the boot. Within those goals, any lacing style and tightness you like is good - as long as you aren't numb!