Correct, MPN, as a general rule, any length of service in theatre which is curtailed by death or disability due to service will be sufficient to qualify for the relevant British campaign medal.
With regards to a Purple Star equivalent, we did of course have wound stripes in the First World War, and these were re-introduced in 1944 in the form of a cloth badge worn on the battledress. As far as I am aware they have not been issued since WW2, certainly not for recent conflicts.