[blue62]

Cris,
Your P1128 and P1130 codes are telling you that the fuel system on both banks has reached the rich limit trigger point. So your fuel trims should be showing negative trims or taking fuel away. Your P0455 is as you know a fuel tank ventilation major leak.
So what is happening is you have a situation where fuel fumes from the fuel tank are coming into the intake from the EVAP system.
Causing hard starting when hot and most likely the P1128 and P1130 codes

Because of the above condition when the car is hot or warm it has trouble starting because the fuel mixture is to rich.
When you step on the gas pedal the reason that it helps is because you are giving the engine more air not more gas. Thus leaning the fuel mixture in the cylinders out and allowing the engine to start.

On a car with electronic fuel injection the ECU controls the fuel.
All that happens when you step on the gas pedal is the throttle plate opens farther allowing more air in and also the throttle position sensor tell the ECU/DME the throttle plate position.