#1 & #2:
Deciding between the <B>natural and imitation leather cord</B> is kind of tough. Personally, I prefer the natural cord, because I don't feel I have to defend my decision to use imitation product when people ask what the cord is. The imitation is a bit sleeker and regular. The natural is a little irregular (but still nice). Both of these hold their coiled shape a bit more than you might want, when you have only a pendant on them.
This can be a problem if your necklaces are hanging from a display. If they are pinned to a display, then it isn't a problem. They straighten out with a little wear.
#3 & #4:
The <B>Waxed cotton</B> is very nice. I like it a lot.
The <B>Waxed linen</B> comes in nice colors, but is much better for stringing than for pendants. It can unravel when too much is left exposed.
#5.
Hemp cord is great for macrame', and the dyed colors are nice and bright. It isn't my favorite for pendants, but for certain pendants and markets, it is very appropriate. (Rasta-themed pendants, smoking accessory stores, etc.)
#6
Sorry, we sell the <B>variegated rattail only by the spool. In your order for other stuff, we can include a few inches as a sample, if that would be any help....
And we don't stock any cording, rattail or otherwise, over 3mm. Not much is available, in the jewelry industry, over 3mm. I think that is because most bead holes are .3 to 2mm.