Legofan Minifig

Yep, that was exactly the problem. Thanks!

Is the trapdoor placed on the top of the block, opening downwards, or on the bottom of the block, opening upwards?

@Kumasasa: Mrpingouin got it to work with /effect. Why is this invalid?

/effect @e glowing 1000000 0 true

Since I was able to make myself glow, as well as the armor stands and most mobs (all if you don't count the bosses), clearly the code works. Plus, I continued glowing even after using /effect @p clear, which successfully showed "Cleared all effects" in the chat bar, proving that the command block does output every tick.

Just to see if it would work, I manually typed /effect @e[type=ItemFrame] glowing into the chat box, and I got the attached screenshot as a result. Since there's an item frame in the picture, obviously there's an ItemFrame in existence to make glow.

And since you asked so nicely, I've attached the crash report. Not that I have any idea how to read it, so maybe you can get something useful out of it.

P.S. The glow's not working properly in your screenshot, either. The command block is glowing, in spite of not being an entity (from the fact that it can't exist in the same coordinates as another block, as well as its not being given an Entity ID - http://minecraft.gamepedia.com/Data_values/Entity_IDs - I'm assuming that it's not an entity) and you can see the texture, not just the glow, through the stone block. Compare to the boat, which you managed to get working, which you can't see the boat through the stone, only its glow.

Nope.

Still around in 1.9.2 - MC-101100

@Brian: Similar, but not quite the same. That one specifies that it's on fast graphics; I didn't have fast graphics enabled.

Confirmed for 1.8-pre1.

Confirmed for 1.8-pre1. Similar to the linked MC-6932, Primed TNT will appear black in low light levels, even in the Overworld. Attaching a picture. Also see my comment about light levels in MC-6932; I think the same issue applies here.

Confirmed in 1.8-pre1.
Attached a .zip with a few files in it - the TNT cart gets darker or lighter depending on the light level, as opposed to being black in light level 0 and normal in 1 and higher.

...it's called the Nether, Ben... 😛
If you want a world with Nether, just put spawn in the Nether and remove the portal. No exit. Mwahahaha. 😛
Same thing with the End.

Invalid. Most mobs don't attack players when shot by a bow.

Confirmed for 1.8-pre1. Also works if the wolf is running around and you make it sit while it's moving.

Confirmed as early as 1.7.2. I haven't played earlier versions of MC so IDK if it did this since the beginning or not.

I'm not seeing anything unusual at the specified coordinates. No stone growing on trees. Played in 1.8-pre1.

The bug is somewhat fixed in 1.8-pre1. If you use the command from the description of the bug, the first time the entity is inside the block, the second time it starts suffocating, and the third time the falling sand doesn't appear (though the first two don't disappear).

Fixed in 1.8-pre1. I was in Creative, though, so IDK if that affects anything. The zombie took damage from the "bugged stick" just like a punch. And it died after twenty-odd hits from the two combined, just like a zombie should.

Confirmed for 14w25b, but I don't remember seeing this bug since then. IDK if it's fixed or not though based on that alone.

Confirmed for 1.8-pre1.

Confirmed for 1.8-pre1.