> On starting a new hive is it better to keep them crowded  for a
> month or so (in one brood box) or should I give them plenty of room...
 
This depends on many things:  Time of year, size of split, presence or
absence of flow, coldest weather expected, where you live, etc.
 
Generally speaking, small hives (nucs should be confined to a space they
can control in terms of humidity and temperature and that they can defend
from wax moths and predators as well as other bees, but which permits them
to expand and contains sufficient feed to carry them from one visit to the
next.
 
Larger hives during flow conditions and warm weather should be given about
twice the space they appear to actually need.  Sufficient openings for
ventillation must be available in case the weather gets hot, while
they should still be confined sufficiently that they do not withdraw
from the supers during a cold night or rainy day due to cold.
 
In the fall, when flows are unlikely large colonies should be reduced to
two standard supers or less for wintering.
 
Allen