badger away we all think we all like to be asked brewing questions because it allows us to pass knowelge of our experience and seprate prefrences...
in reply to 1, i am sorry you are confused, you can stop fermentation close to a desired flavor be never exactally... cold crashing works, you need to put it some where cold, definatly at or just slightly below 32F degrees... this will casue in most yeast 80-90% dormanciy in a 24-48 hour periode. The achohal content will not allow the wort to freeze quickly and you must be careful because if it freezes it will not clear properly, according to a text i have it refers to "chill haze" which will cause discoloration or hazy cider or beer... During cold crash you will see your yeast begin to drop out of solution in the form of less on the bottom of the fermenter. This will reduce the ammount of yeast in solution (provided you dont shake it up and disturb the less) by roughtly 75-80%,some yeast will remain in solution despite all your efforts. After no more then 48hours you should remove the wort from the fridge and rack it into a prechilled container (simply another fermenter which has been keep at roughly the same tempature as your now chilled wort. Rack the cider off the less into the second container, careful not to disturb the less and get it back into solution. After you have racked as much cider as possiable with out disturbing the yeast take and SG reading and taste... this is only becasue there will have been a change since you started cold crashing because it will have taken time to stop fermentation. Before the brew warms above 40 degrees you will need to put in an ammount of Camp Tabs and K-Sorb or other anit-yeast chems. try and keep the tempature down for the nest 6-12 hours so the chemicals can do thier work and knock any remaining yeast out. Then for another 12-24 hours return to below 32F degrees to have dead yeast fall out of solution, as well as likely 80-90% of any remaining yeast left in solution. At this point your yeast count in neligable and even if they do re-animate from cold crash they will not be able to reporduce and the current generation will die off with in 24 hours... this the simplest and most effective way to stop fermentation completely but you will have a differnt in flavor from when you decided to stop to when you finally finnish. After you have completed this, taste and if you like it then bottle it. Unless you have a carbonateing setup you can not carbonate this, there are no yeast left to produce carbonation.
Theoretically you can reduce the ammount of yeast by cold crashing over and over again by nearly 95% but this will most definatly cause chil haze if not done properly and then you would not have to worry about a large ammount of fermentation due to the surviving yeast, you could add priming sugar and bottle with out much worry of bottle bombs because of such a low yeast count.
The other alternative has already been explained, you can let ferment completely and backsweeten, which is infinatly simpler and farm more consistant because you literally sweeten to taste, its how you want it and its as persice as you want it to be.
to reply to number 2: He is not wrong, he is merely telling you what he believes is the best way, brewing is done completely to preference and ability.
To reply to 3: Yes this is a personal choice, there is no standard on how to produce home made hard cider, its a craft. It would be like saying that there is only one way to make chocolate chip cookies, which there are actully thousands of ways to make them, same with cider.
As stated before, I would not sugest cold crashing or useing chemical preservatives at all, they are extra added variables and are extra possiable headakes if done incorrectly or somtimes even if done correctly... I would sugest getting a couple of batches the old fashioned way done under your belt before you start playing with the chemicals and gagets. And remember Brewing is personal preference, and what you believe is with in your ability to do with out causeing injuy or death to yourself, and of course somtimes money is an object. Technique is only 15-20% of this hobby... say another 30-35% is ingeedants, and time, and equipment. 5-10% is luck, and the last and alrgest chunck of all that last 40-45% is just plain ass what you want out of brewin, your preference, and peception of what you want... So rule number one is "that there is no concreat rules", except rule 0, and rule zero is "make sure everything is really damn clean"
I think you should try jumping in and getting your feet wet
cheers