proper tire pressure

Depends on weight on tire and max speed you use, and wont go over for even a minute. I am able to calculate it for you , if you give me more information.

From tires I need next. Only if they are standard load or XL/Extraload/ reinforced. Then I can google for loadindex or maximum load, speedcode is not that important , and pressure for wich maxload is calculated depends on SL or XL Determining the weigts on axles, or better seperate wheels, is the hardest part in it all. Carmaker uses GAWR'S for that, but then for fully loaded. The loading for the situation and empty weight helps to estimate normal use weights.

Probably 30-32 PSI. Have you looked at the driver's side door tag?

Yes