1) My Suggestion from your list for a daily carry light?
The E2. It is amazing.
I carry mine practically everywhere (often when I have an M2 and/or E1 as well!) It is one of the lights I use the most.
I would suggest the D2 (with PocketClip) as a daily carry light unless you want a pouch for the 6P.
2) How waterproof are SureFires?
The ones you mention are all water resistant using quality o-ring seals. The most water-resistant of the SureFires you list is the 6P (new version) that has a fully waterproof double o-ring sealed LockOut TailCap switch, however, the Lexan Lens Bezel is not 'waterproof', rather very highly water-resistant. (basically, unless you get a certified version, there is a chance the lens seal will leak underwater)
The Millennium Series M2 & M3 are designed to be waterproof, as are the M3T, M4 & M6 with Pyrex Lenses. However certification is advised if the flashlight is required to be transported or used underwater.
The E2 is the natural choice from the list unless you need more light was higher water-resistance in which case I'd suggest a new 6P. The G2 is a very useful utility flashlight, but without a PocketClip, daily carry would require a pouch. If you get a 6P or G2, I suggest a Lanyard.
Does this help?
Al