What's with these notes about all the obstacles? If I can fly the
take-off minimums and/or fly the ODP (if specified, not in the example
below), does such keep me clear of the noted obstacles? (I think the
answer is yes, but then-- what's the point?)

Here's an explanation from the FAA's Instrument Procedures Handbook
(http://av-info.faa.gov/terps/IPH.htm):

Obstacles that are located within 1 NM of the DER [departure end of the
runway] and penetrate the 40:1 OCS [obstacle clearance surface] are referred
to as “low, close-in obstacles.” The standard ROC [required obstacle
clearance] of 48 feet per NM to clear these obstacles would require a climb
gradient greater than 200 feet per NM for a very short distance, only until
the aircraft was 200 feet above the DER. To eliminate publishing an excessive
climb gradient, the obstacle AGL/MSL height and location relative to the DER
is noted in the Take-off Minimums and (OBSTACLE) Departure Procedures section
of a given TPP booklet. The purpose of this note is to identify the obstacle
and alert the pilot to the height and location of the obstacle so they can be
avoided.