The "perfect" taste has gone. I need some assistance to figure out if anything is wrong. This is what I've done so far:
I started making Blackberry wine with juice processed from fresh picked fruit.
Average Temp 74 degrees Fahrenheit
PRIMARY - SG 1.096 on 20 AUG 07:00AM
SECONDARY - SG 1.023 22 AUG 09:30PM Sampled a sip about two Tablespoons ...taste is very good.
Fermentation was like a coffee percolator for the first three days then gradually slowed to a bubble every 5 minutes just before 1st racking.
1st RACK - SG 0.993 on 30 AUG 11:15PM ADDED 3 crushed Campden dissolved in 1.5oz warm water. Sampled and the taste is very acidic and slightly bitter, no unusual smells. I added 27oz of cool water to top off 5 gal carboy. NOTE to self - I need to perfect my racking procedures so I don't waste as much wine with future rackings.
I used an acid tester and it appears that the color change occurred at 0.6% (6cc's of neutralizer - not sure what this means -- Do I add anything at this time?) I dumped the rest of the neutralizer in, all 10cc's and the color continued to change to deep navy/black. The secondary seem to start clearing the wine fairly well. Did manage to rack some lees into the carboy not many but some. Airlock has begun to bubble.
The wine has lost all sweetness. At this point I don't know if anything is wrong, I'm awaiting responses to my myriad of questions. SG stated above has been converted for temp difference.

You didn't mention when you tasted, before or after the campden. I am assuming before you added campden.

1. It is not unusual to lose quite a bit of must on the racking from the primary. A small amount of lees shouldn't be a problem in the secondary. I am assuming that will be racked again in about 3 weeks. When I start my wine out I usually try to plan on the loss. If you plan to rack to a 5 gallon carboy start out the primary with 6 gallons and it will work out better. If you only lost 27 ounces out of 640 ounces (4%), I'm impressed. I usually plan on losing up to 20%, depending on what I am making.

2. I normally add 1 crushed campden per gallon.

3. The acid at this point is OK. Yes, 6cc to get a color change means .60%. In black berry wine I would expect the acid to be a little higher than .60%. Measuring acid this way is not rocket science and there will be more color change if you keep adding. The .60% is a good starting point and sometime between now and when you bottle you will want to check the acid again. Sometimes things you add like oak etc. will increase the acid.

4. I wouldn't expect my wine to taste good at this point. Some of that bitey taste is just that the wine is very green. It needs to age. The flavor will smooth out as the wine ages. Towards the end of aging you can bring that acid down towards .55% if you like.

I think you are off to a good start. I think your wine will be fine. A question that comes up a lot. What should I use to top off the carboy? Water is OK. Sometimes I use off the shelf juice. The sugar will ferment out. If you use a juice that has a preservative it may sweeten the wine slightly. May not be noticeable.

Campden: I use 1 crushed campden per gallon at first racking out of the primary. I then use either 1 crushed campden per gallon every other racking or 1/2 crushed campden per gallon every racking. The campden will keep you wine from oxidizing. If you ever add potassium sorbate to your wine make sure you also add campden at the same time.

Other chemicals: Pectic enzyme will help clear the fruit wines.