Peter, accurate casting is the be all and end all of sucsesful feeder fishing.The main use of the feeder is to build up a bed of bait in the same area.There are many ways of improving your casting accuracy.If your reel has a line clip clip the line into this once you have cast your required distance.This will ensure that you can only cast the same distance.Using an over head cast and aiming at a set far bank feature will help direction.If you are expecting big fish that will take line,instead of "clipping up" put an (wide)elastic band around the spool.This will still control the distance but still enable line to be taken against the drag.
As for your last question it is very hard to use one ledger rod and one float rod at the same time.Watching for bites can be dificult.An electric alarm can help.When feeder fishing regular casting helps due to the bed of bait being built and topped up.Far better to use just one rod or if you must use two use two the same.
