Can anyone provide suggestions as to what changes I should make when I make my cider again?
1. back off the sugar - it makes it higher alcohol but washes out the apple taste. The most I ever use in a batch is 2lb sugar or 3lb honey, and that is with early season apples that have lower sugar. Late season batches mostly have no added sugar. All juices are different, but my experience is more sugar = less apple taste, so use sparingly.
2. Try a different yeast. I've got poor results from CdB. Others have had good results, which is likely due to differences in juice mix and how different yeast respond. I've had best results with ale and wheat yeasts, they are easier to manage.
3. Use a better bottle for your primary fermentation. They are easier to handle, you can see what is going on, and you never have to worry about whether your seals are 100% secure. You want to eliminate potential air contact wherever you can. If you have been using the fermentation bucket for a while to make beer in, and are confident that it will keep a tight seal for 3 weeks, then I could see using the bucket to save a little money, but for easy of use and peace of mind, I'd still get the BB.
4. Start with the best juice you can find, preferably unpasteurized from the press, but if you cant find that you still want to start with the best tasting juice you can find. The yeast will work with the apple flavor, but they cant create apple flavor. a lot of table juice is crap for fermenting. buy some half gallons and see what tastes best. Initial sweetness is not as important, you want a lot of apple flavor in the middle of your mouth and a decently tart finish.
I still have my original batch too...is it fixable?
Wait till it finishes out. I believe David is right, it probably has another 2 weeks or so to go. Check it at 2 weeks and every week until the sg stays stable, probably at 1.000 give or take a few points. At that point, you should check it again for any vinegar taste. Sometimes a little bit of a vinegar tang at the finish is OK, but if it has a strong vinegar taste, that will not get better. vinegar feeds on the alcohol and you want it out of your brewing area.
However - make sure you dont confuse other strong acids with vinegar. Cider acids can be pretty harsh tasting, esp citric and malic, but they will mellow over time. vinegar gets worse. If it is really got the vinegar bug then maybe you can give it to someone who wants to make vinegar. It usually makes good vinegar, but you dont want it around your brew area.