Just by raising the tire pressure to 35 PSI will make it stiffer than if they are at 32 PSI.

Costs nothing and makes quite a difference. Try it out!

Absolutely, that's why I set mine higher. It's not dangerous at high speeds either. One advantage is that you reduce rolling resistance which will save a few cents on gas, but on the other hand you loose contact patch area which could land you in a ditch on rainy days. The one serious problem is premature tire wear which will commence at the center of the tire. Personally, that does not bother me too much since the camber at all four wheels is very neutral. On vehicles like the X5 where the rear wheels have a noticeable negative camber, it would seem that the contact patch would move a bit to the inside of the tires with higher inflation (since tire tends to get narrower at speed), thereby promoting the classin excessive inside wear on the tires that's so common with the negative camber suspension geometry. I'd like to hear more on this.