Do I interpret your wiring diagrams correctly? You want to establish a two-way communication using these 433MHz modules? These are thought for a strict one way communication where the code is repeated as long as some remote control button is pressed. I don't know if you get this reliable enough to be used as as serial radio communication device.
If you look at the code it explicitly depends on getting the code repeatedly. Only under perfect circumstances where no noise is on the air you get each transmitted byte correctly.