OK so a couple of things here need some work.
But it can all be fixed.
New screws - you seem to be missing some.
New top plate - yours is now broken ( but may still be flyable )
LittleBee ESC - Needs fixing back down and could do with some tape/padding under neath it to protect from shorts.
Flight Stack - swap out those metal standoffs for nylon ones. the mounting holes on a PDB and FC are some time grounding points.
Try to mount it...... Nylon stand off > PDB > Nylon stand off > FC
Rasing the PDB off the carbon base plate will protect your from shorts.
Refit the connectors on the FC
RX - refit the connector there too, relocate the RX to the rear of the frame. It will get better signal if there is less carbon between it and the TX
Bad connections will give poor conductivity - bad power and bad signal.
But as I said it can all be fixed.