Yes it's safe to cut spring as long as you use a grinder or a cut off wheel and not a torch.

 

I've cut springs before, if done right its a cheap way to lower the car but i wouldn't do more than one turn.

 

Cutting your springs will increase your springs rates. Also, unless done perfectly you will almost never get equal spring rates between the springs after they have been cut. The spring won't want to sit in the perches right either. Don't be cheap, buy the new springs.