Indentations are OK as long as it is not painful or uncomfortable. I bought a helmet (for dirt biking) on sale once, just a little too small, thought the same thing, that it would ease up. Never did get used to it, wore it off and on, but kept going back to my older one that fit better right from the start.
Now I use the tight one for AX
Hope your helmet works out for you! You will really only wear it for maybe 30 minutes at a time until you become a racer right?
BTW - Caliper rebuilds tonight........
-Chris