<human>: Hi Random Metabolism Expert/Guru/Savant/Experience:

Stats:
Male
27
6'2"
185 lbs. (bf% 15-20?)

I am on week 4 of the Cyclical Ketogenic Diet. 
I have a hard time consuming calories on the diet, even on carb-up days. I am am hitting my macro's of 60-65% fat, 30-35% protein 5-7% carbs.
Low Carb Days: 1950-2250 calories
Carb-Up Day: 3000-3400 calories

I have seen many calorie calculators, I am just curious how accurate they are? These calculators are putting my maintainence at anywhere from 2,700 - 3,050 per day.

Question: Has 4 weeks of ~2000 too large a deficet? Will this potentially hurt my metabolism should I end the CKD? I worry about a rebound off this diet, or potential damage to my metabolism. I never calculated calories before starting the diet to see what was keeping me at my 189-194 range for a period of ~2 years. 

Info: I have been losing weight each week, after 3 weeks my after carb-up start has seen a loss from 194.5 down to 184.5. Roughly 10 lbs. I have not yet lost strength in any exercises at the gym. 
I figure about 4-5 is from water, and hopefully 2 lbs of fat per week. 
Is it possible to have muscle loss without loss in strength?

Can you provide a brief rundown of the text in within 3 sentences?
<bot>: 2,000-2200 calorie mark for my biostats: is this safe? Will this permantly change my metabolism going back to what a calculator will put my (new weight) calorie maintainence at?