Glad you found a good Sprint, try to keep it in good condition.
Is there any marking visible on the springs themselves? That way you can tell if they are the original ones. Apart from that, the previous owner(s) may have cut a coil resulting, in time, to shifting.
A good option is to get Sachs/Boge original springs, they are the same as the Series I Alfa 33. They are not that expensive really.
With lowered springs (say, 30mm), some twisting of the springs is expectable and it is not dangerous IMO. If you apply downward pressure to the bonnet/hatch, does the car rebound correctly (that is, once)? Are the shocks firm enough? Also, have you checked the bushes? A suspension performing less than optimally can indeed be dangerous, esp. during aggresive driving conditions. Also, your braking stability shall suffer.
My opinion is, see to it asap.