1991 Camaro RS: Couple Questions

1) Hi, I was wondering if any of you knew how to tweak the idle on this car? It's a 305 V8 5.0L. It tends to idle and run way too high RPMs than I'm used to seeing. When i'm going 70mph it's at 4500rpms. It's usually, except in 3rd gear (it's automatic btw) running very close to the orange and red zone, It will be in the red zone when I pass 80mph. I'm wondering if the Tach is off or if my idle is just set way too high. Btw the car doesn't have a thermostat in it right now, but I'll be putting one in soon.

2) My car doesn't have a thermostat in it right now, but should I replace the bottom radiator hose, because when the engine runs in high rpms, I can see the hose sucking and almost going flat from it pulling coolant from the radiator. I know I need the one with the spring in it for sure, but I was wondering if not having a thermostat makes it pull harder or what?