In reply to hisingh:
For Q1, This is more of a syntax issue. ##0 and ##1 are a sequence concatenation operators. Event controls can only be placed at the beginning of a sequence expression. Each each sequence expression can only have one clock. You need to use concatenation to have multiple clocks. In your example there is no difference between ##0 or ##1 because the posedge and negedge can never overlap.
For Q2, since you used the non-overlapping implication operator |=>, the consequent starts on the next @(Sig) event.