in a cave they can spawn in the day or in any other shaded area the has level 7 light or darker. if a doungen is above ground and you are on atleast at an easy difficulty and the spawner is exposed to light and the spawner is a skeleton or zombie the spawner will spawn mobs and they will burn in the day light
No, mobs will not spawn in water or ontop of half slabs.
In Minecraft Classic, mobs can't spawn, so they can't exist naturally. If you play the Survival Test, and when mobs spawn there, you can save it and open it in creative mode so then the mobs can stay there. However, in Minecraft Creative Mode, mobs can spawn, but they can't hurt you because you have no healthbar.
No, the AI for mobs in minecraft has been improved so mobs don't spawn in strange places. You can manually spawn them in lava with that mob's egg.
All hostile mobs spawn on easy difficulty.
The only mob that can spawn in water is currently a squid.
Grass and stone blocks.
If you mean by mob egg-type things, you can't. Only darkness can cause mobs to spawn.
Yes, mobs can spawn on netherrack in Minecraft. In the Nether, hostile mobs such as ghasts, blazes, and magma cubes can spawn on netherrack, provided the light level is low enough and other spawning conditions are met. However, passive mobs do not spawn in the Nether at all.
Yes, in the Nether Zombie Pigmen spawn on the netherrack but I don't think they spawn on Netherrack in the Overworld.
You name the spawn egg dinnerbone or grumm
No, there are preset spawners undrground and hidden ones in blocks.
Yes, but the Pigmen and Ghasts won't spawn.