There are many different types of play sand. SW hobbyists search out SouthDown playsand (now called Old Kastle) because it is finely crushed coral/aragonite, which helps buffer a tank and keep pH up. Most playsands are not in fact going to impact pH at all, and are fine to use.
For cleaning: Don't use a regular siphon, just use the hose. Slower, yes, but it works. I lose about 1/4 cup of sand with each siphoning, on a 55, and less than a 1/4 teaspoon on the smaller gallon tanks (currently have 2 5 gallons, and one that's 2 1/2). Keep the end of the hose about 1/2 above the surface, and you'll get most of the waste. Make sure you either have lots of rooted plants, digging fish, and a thin layer *OR* do not disturb the depths at all (means no digging fish as well).
In my newt tank, I put about 1/4 inch of sand, then topped it with 1.5 inches of aquatic plantic soil. It works nicely, and I don't mind it mixing.