How do you determine whether a salt is soluble or insoluble? OR are these salts soluble or insoluble?

There are solubility tables for salts, so you can look it up. The first two are soluble, I'm not so sure about PbF2. There are some general rules about solubility. Most Column I salts (the alkali metals) are soluble. Halide salts of the Column II salts (alkaline earth metals) are soluble. Note that solubility and insolubility are two ends of a continuum, and there is a grey area inbetween for slightly soluble salts. Generally, a salt that has a solubility of 20 g/L or more is soluble; a salt that has a solubility of 1 gram/L or less is insoluble.