1/Difference between design pressure of upstream equipment (steam heater) and downstream equipment (usually codensate receiver).Of course,one may decides to consider the same design pressure for both results in no need to spec break but realy wouldn't be economical.

2/saturated or subcooled condensate,depending on steam trap situation with regard to steam heater.

3/depends on downstream pressure may be saturated condensate or liquid/vapor n addition to answer by fallah, following is pointed out:
a. "Steam condensate design pressure" was discussed in a thread dated Sep 13, 2009, in the forum of "Refining, Hydrocarbons, Oil and Gas". You can find answers there. Condensate design pressure should be that of the steam upstream the trap, unless whole condensate line has: PRV, no valve, only locked open gate valves.
b. Even if condensate gets a bit subcooled in the line upstream of trap, flashing occurs downstream due to pressure drop, which results in two phase flow (liquid vapor).

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