That would be correct about the stars - the servicemen and women were only entitled to earn a maximum of five. Those who qualified for more received a clasp to the riband, only one clasp to a riband being allowed.
The stars could carry the following clasps:
1939-45 - Battle of Britain
Atlantic - Air Crew Europe or France & Germany
Air Crew Europe - Atlantic or France & Germany
Africa - North Africa 1940-43 (Naval) or 8th Army or 1st Army
Pacific - Burma
Burma - Pacific
Italy - none
France & Germany - Atlantic or Air Crew Europe.
(taken from "The Observer's Book of British Awards and Medals" - Edward C Joslin)
Regarding the Pacific and Burma Stars: from
http://www.veterans.gc.ca/eng/remembrance/medals-decorations/wearing-medals/ww11medals "Pacific Star and Burma Star
The Pacific Star and the Burma Star are alternative awards. Personnel, who by their service qualified for both the Pacific and the Burma Stars, will be awarded only the campaign star for which they first qualified. They will, however, be awarded a clasp to show that they rendered service which qualified for the second star."
Terms
Burma Star
Awarded for one day or more of operational service during the Burma campaign, between 11 December 1941 and 02 September 1945.
Terms
Pacific Star
The Star was awarded for one day or more of operational service in the Pacific between 08 December 1941 and 02 September 1945.
Re the swimming medal: it's quite possible this was a simple medal awarded to the winner or whatever, as I have a running medal from Sept 1943 which belonged to my father.