Oliwog,
You can attach the earth wire to any metallic part of the ballast that is not in contact with any of the other wires. The earth wires are used mainly to discharge small stray electrical currents. Also make sure that there is an earth wire running from your ballast to the socket plug.

As for the reflector it looks like the standard reflector with a mogul socket. And your lamp looks like it should fit fine. I had the same problem with my lamp, it is a little difficult to screw in, you feel like you are gonna break the thing, but its actually quite strong. Just make sure you apply enough force to keep the lamp in your grip but not too much lije the glass is going to break. Just keep screwing :-) It WILL fit, if it feels like its screwed in place, check to see where the metal part of the bulb is in relation to the socket, the metal part should be completely in the socket, if its a little out, screw some more :-)

Regarding the envirolights, im assuming you are talking about compact fluorescent lights, some of them can fit into the socket and run without a problem but make sure your envirolights have an auto ballast, if your lights look like this: http://www.agrolite.com/espanol/agrolite.php
and have a greenish thingy at the end where it connects to the socket then you should have no trouble screwing it into a proper ballast because the lights contain their own, which will just reducde the current/wattage that end up going to the lamp.

About hanging lights, chains work, good against heat and such, i personally use strong nylon rope found at almost any do it yourself store, as long as what you are using fits, and can support the weight of the lamp it will work.
Good luck with the grow man! Peace