You are correct......the Founders viewed a standing army as a threat to liberty. The memory of the British soldiers in their midst was fresh....and the second amendment was written as it was "A well regulated Militia being necessary to the security of a free State, the right of the people to keep and bear Arms shall not be infringed." to recognize the fact that the common defense was to be provided by the whole of the people. There was likewise a very healthy distrust of the FEDERAL government that was to be created. The concern was that it was going to be all powerful and essentially crush the individual states. The second amendment, when viewed with in the context of history, is fully comprehensible:
"A well regulated militia being necessary to the security of a free state".......meant that the whole of the people were to be armed....so that they could defend themselves and their states from enemies foreign and domestic.
And the hard, hard lesson of the First World War was that lack of a standing army made timely mobilization impossible when large bodies of troops were required. We were lucky, in that war, that we had 9+ months to assemble our troops (who were dismally short of armaments, it must be remembered).
The idea of not having a standing army is fine, so long as one is never seriously threatened by another nation which does have a standing army. To fail to establish a standing army in such cases is to commit suicide.
And "regulated", as it meant in the day, was to "make regular".
The term was use by clock and watchsmiths. In fact, the particularly accurate pendulum wallclocks were termed "regulators", by which men would time their watches and lesser clocks from.
Thus a regulated militia meant that they were expected to have laid out emergency plans for their communities and have regular shooting excersizes to hone and keep their skills up, turkey shoots and schutzenfests.
If only our modern politicians and "scholars" were just half as intellectually honest as the founders - how much better off we'd be today!!!