What if we had kept control of the panama canal instead of giving it to panama?
The USA might have kept control of the Panama Canal if back in 1903 they had annexed the whole Panama state after it broke away from Colombia in US-sponsored coup, and they eventually given it the same autonomous quasi-state protectorate status as Puerto Rico.
now that would be a possibility - we were still on our imperialism kick back then. Of course, a USA which would annex Panama in 1903 would probably also pick up several more of the carribean/central american states as/when they fail.
Two Part Answer to a Two Part Question ...A related issue: do you think that if Panama had been a US territory, the Third Set of Locks Project would have been implemented in the 1940s/1950s as it was originally planned (the works were started in 1939 but were stopped due to the outbreak of WWII, and lapsed till late 2007) ? And how a super-Panamax compliant Panama Canal would have affected international commerce ?