Are you using 100% powered rails? If so, the unpowered version acts as a brake, explaining the problem.
Does this work on Cobblestone Walls or Mossy Cobblestone Walls? It may be because of their 1.5-block property.
What is VBO?
Try shift-clicking the piston while holding redstone dust. If this works, then this is a bug.
What is an inverted daylight sensor?
I think this isn't a bug. Transparent blocks (non-opaque) like the two you named are unable to transmit redstone signals. Try this with a glass block being directly powered by a redstone repeater facing it - tell me if it does anything.
Survival. I was actually told that Zombie Pigmen remember the exact details (maybe uuid etc.) of the player that attacked them, and that's why I reported this. Thanks for the explanation.
I used /gamerule keepInventory 1 AND /gamerule keepInventory true. My question in this report is why it happened after another version was released.
It may be because they passed through too quickly, since it takes time to catch fire.