First off never zap test crystals themselves just in case they are lye which they very seldom are. I have had crystals such as this form on other soaps at times and even if they do not wash off they are fine. Normally as DeeAnna mentioned we figure they are Sodium Carbonate crystals but I have also had crystals form when I used sodium citrate or lemon juice as a chelator. Sometimes the crystals would be really dense little spots like yours.
Acceleration means your soap batter thickens quickly and it is pretty common when making pine tar soap. BTW, as a new soaper you did not choose the easiest soap to make and I congratulate you that your pine tar soap looks great. Pine tar will cause the batter to thicken (accelerate) faster than other formulas. This is an issue you will learn about as you get further into soap making. Some fragrances can be difficult and cause bad acceleration. You do not always have to cover soap it depends if you want your soap to gel, or recipe, etc. That is a subject for another post. As a new soaper, it is worth spending time reading through DeeAnna's information found here
Soapy Stuff