For a very short section a bit of 9mm rope, say 10m would work. This would give you a 5m recoverable abseil. However, don't try and lower yourself hand over hand. On wet rope this is almost certainly going to end badly. You can easily make a temporary harness out of a long sling and krab. Use something like a belay plate as a friction device. You can also use karabiners as a friction device, but the setup isn't straighforward and is easy to get wrong.
However, practice somewhere safe first as it's easy to make a fatal mistake. Regarding anchors looping a sling, or the rope, around a spike is probably the most foolproof method. Unless you have experience I wouldn't recommend using anything like a jammed nut.
Can't remember enough details about both to do a comparison. However, all the difficulties of Cneifon are in the first 80ft. After that it's exposed, but easy scrambling over pinnacles. There isn't much protection on the first bit, so still fairly serious even when using a rope. A great route.
To add to Alexander's definition of n00b, a lot of people would refer to these as lusers ie people who are unwilling to learn anything and expect you to do all their research/work for them. An essential tool for dealing with them is a LART (luser attitude readjustment tool) aka big baseball bat.