sounds way too complicated !

my advice is to
just do something simple to start.
especially if you havent gotten anything on the screen yet.

the problem with such a loop, depending on your physics engine,
is that the call to the physics engine isnt going to improve by passing smaller values. it will still take the same time to calculate (roughly, same number of obj colliding), the items just wont be going as far.

i could be wrong but thats my experience