Totally agree with the first point and it is something that will tune moving forwards after we launch... we want to work with the players to expand the ideas we've presented!
The darkness detection is tuned down a lot depending on the size of the shadow and is something we are constantly tweaking, in the meantime if you have a flashlight, just put it down beside you (switched on). Also, increase your fortitude level in your stats... or eat a glowing mushroom...
The puzzle is intended to take a little time and hold people up a bit. You can bribe it if you are impatient but freeman dollars are quite valuable.