I'll try and answer those i can
"1) I recall reading that, when it came to damage absorbancy, regular armor IV is more efficient (when looking at tonnage) than shields up to level III. What is the deal with armor, shields and their usefullness? If anybody cares to elaborate, would you bother telling me about the other armors and shields (emissive, phased, organic, etc)"
Not sure on this, haven't delved THAT deep yet..
"2) When it comes to designing your race at the game setup screen, what are the best Advanced Race technologies - Organic, Crystalline, Psychic, Temporal(?) or Religious?"
Well, in honesty, try them all and see what fits your style of play. They all have advantages/disadvantages.
"3) Early game considerations - colonization tips, scouting, "build orders", good early ship designs, good early-game research projects, etc."
Kinda hard to answer in a short answer. again, maybe see #2? Though one thing that has "saved" me early on is a space station/yard facility with a missile. helps an early escort or frigate from glassing your homeworld(s).
"4) Are there any good sites out there for SEIV? I found spaceempires.org, but it seems they had a recent server crash or something."
Kuat drives (Star Wars)
(
http://se4kdy.cyberwars.com/)
and Universal Shipyards
(
http://universalshipyards.tripod.com/ )
and New Age Drives (Star Tek) (
http://www.angelfire.com/tv2/NewAgeShipyards/intro.html )
come to mind. Hmm, hope I got these right. I'll get the URL's in a bit...unless someone beats me to it
"5) I plan to play single player for awhile to re-familiarize myself with SEIV - but I plan to delve into PBW (perhaps quite heavily). Are there any, let's say, not-so-good players (can't really put that politely) who would like to include me in their PBW games?"
Hehe, well I stink so bad the AI beats me most of the time (I keep trying different things

)
"6) Speaking of which, is it that much extra fooling around including Custom Race Styles in games, or is it not worth the trouble (and just stick with the defaults)?"
Hehe, me trying to help with a B5 conVersion has hastened my hair loss

but has been fun too. I also have a race style "published" (Hampsterattii) and had a bLast making them...just tweaked a default AI in research and designcreation.txt a bit. It can be fun if ya don't try to be TOO ambitious, at least at first. IMHO anyways.
Have fun...
[ 09 April 2002: Message edited by: pathfinder ]