Ik Zelf

Reusing the entity would be useful for keeping movement vectors, and so forth. It just would make things a lot more interesting, IMO.

confirmend, MC-58934

Did summoning an item frame itself work?
Afaik, this is only possible when specifying the coords of the block it is placed on, so this is merely a problem of specification. Related to 49835

duplicate or related to MC-957, related to MC-3114, but confirmed.

The block updates, but the redstone does not accordingly.

Also, this is a bug related to MC-6781, which is the bug that makes this possible.

Also, repeaters and comperator particles are done wrongly. I think the particles don't have invisible parts, and the (normally invisible) parts are now painted black

Dupe, search before posting, had that too. Look MC-6739, this one was the first.

Also, repeaters and comperator particles are done wrongly. I think the particles don't have invisible parts, and the (normally invisible) parts are now painted black.
(the repeater torch stick particles have one row of the normal torch texture, and one row black (on the 'left'))

This is a normal update bug. I had several ones too back in the 1.3, when playing both SP and MP.
When you place something on the non-updated block, it will update and realize this is actually another block, and thus replacing textures.

-Ikzelf1248