If you add fermentable sugar even if you are carbonating it, it will just ferment out in the bottle and you will lose all sweetness. You need to use unfermentables unless you are going for still cider in which case you need to kill the yeast with Potasium sorbate and then sweeten.
The easiest...
Yes all beers will do, but it is a source of food for microbes and no matter how sterile you FV is and how particular you are microbes will get in and can infect it.
Its just good practice IMHO
Yes it will contain a lot of yeast but also a load of other airboune nasties feeding of the yeast.
Personally I transfere it to a secondary FV to get it off anything thats not clean.
Interesting Martin.
Though most of us have found that using Old rosie yeast/dregs and 1 tsp of malic you certainly get a cider with a good farmyard twang. :D:D
If you were living in the south of the NWW region Ie merseyside or cheshire then some of that water came of the River Dee, which has Monsanta Chemical works on its banks. They remove 99.999% of all phenols out of their water before it goes into the river (or they did in the late 80's when I was...