35 psi pressure would be wonderful, however, if you feel that your ride has become bumpy or noisy, etc. you may reduce tire pressure. Do share your experience on 35 psi here, and also mind sharing your city, drive conditions, and no. of persons in car, etc.?
High pressure may not matter in soft tires, however, in case of hard tires, or tires become hard for one reason or the other (as some people say for General tires), then using high air pressure in tires can make the ride quite bumpy and unpleasant.
Regarding tire size, well, if 15" up-sizing is not possible and spacer springs / packing is inevitable, then you may go for 185/70/R14, however, first confirm that whether it will easily fit on your genuine, OEM Rims or not, and not create any problems regarding maneuvering, or touch the body of your car?
One of my friends own 2nd generation Vitz, and he has packing along with 185 mm wide tires (I do not remember the exact specs, but 185 mm width of tire is confirm). I recently came to know through him that the tires touch his car's body (despite spacer springs), and I was surprised. So first confirm, and then also share your experience here.
I just studied today that like tires widths and dias., rims also have specific widths and dias. and if going for 14" size of tire, it does not mean that irrespective of tire specs, any 14" tire will fit on any 14" rim. Many different factors have to be considered! Even 14" rims have different widths like 4.5", 5", or 5.5" (please check, what is the width of your stock, OEM rims?). If a 14" tire requires width of 14" rim to be 5.5", it may not fit on a rim with width of 5", or may make ride extremely unpleasant, or may be dangerous. So, you too do some homework before proceeding for tires changing.