Where can I find the best compendium of US (and worldwide) aviation safety and 
delay statistics?

I am interested in historical accounts of:
 Closely Spaced Parallel Approach accidents and incidents
 Runway Incursion accidents and incidents

Most of the statistics you are interested in (for the United States) are 
available from various US government web pages.  The Bureau of Transportation 
Statistics and the Department of Transportation have statistics about airline 
delays for the major airlines in the United states.  Their web pages include 
both a searchable database (which will show statistics on specific airports and 
airlines in a given time period) and reports, which give a broader summary of 
statistics for a given time period.  (The searchable database does not appear 
to work completely reliably).  Here is the page at the Bureau of Transportation 
statistics with links to on-time statistics (click the "reports and products" 
button for reports or the "searchable database" for the database):

http://199.79.179.77/ntda/oai/

The Federal Aviation Administration has a web page devoted to aviation safety 
data.  They have reports on various topics such as weather related accidents 
and helicopter accidents.  They also have a searchable database.  

Here is the address of the page:
https://www.nasdac.faa.gov/servlet/page?
_pageid=108,110&_dad=nasdac&_schema=NASDAC

And this address should take you straight to the database search form (there 
are three different databases listed under "incidents", but all three appear to 
go to the same place):
https://www.nasdac.faa.gov/pls/nasdac/NASDAC.wwa_app_module.new_instance?
p_moduleid=2165301351

When I queried the accident/incident database for entries containing the 
text "runway incursion", it listed these 6 events going back to 1987 (sorry for 
the extremely long URL):
https://www.nasdac.faa.gov/pls/nasdac/NASDAC.wwv_user_utilities.exec_procedure?
p_session_id=&p_module_id=2165301351&p_version=14&p_arg_names=V_NARR_SRCH&p_arg_
values=Runway+Incursion&p_arg_names=V_RPRT_NBR&p_arg_values=&p_arg_names=V_ACFT_
REGIST_NBR&p_arg_values=&p_arg_names=V_EVENT_STRT_DATE&p_arg_values=&p_arg_names
=V_EVENT_END_DATE&p_arg_values=&p_arg_names=V_LOC_STATE_CODE_STD&p_arg_values=+&
p_arg_names=V_ARPT_NAME_STD&p_arg_values=+&p_arg_names=V_FLTCNDCT_CODE&p_arg_val
ues=+&p_arg_names=V_OPRTR_NSDC_NAME_STD&p_arg_values=+&p_arg_names=V_ACFT_NSDC_M
AKE_STD&p_arg_values=+&p_arg_names=V_ACFT_NSDC_MODEL_STD&p_arg_values=+&p_arg_na
mes=V_ACFT_NSDC_SERIES_STD&p_arg_values=+&p_back_url=NASDAC.wwa_app_module.show%
3Fp_sessionid%3D19118

This web page contains a brief history of runway incursions, mentioning the 
1977 collision at Tenerife Airport that resulted in 583 deaths:

http://www.faa.gov/region/aea/runway_safety/rih.htm

Finally, for information about airline safety outside the United States, the 
Aviation Safety Network appears to have information on airliner accidents 
around the world:

http://aviation-safety.net/index.shtml

I hope this information is helpful to you, and that the web pages I mentioned 
help you find any specific statistics you're interested in.