Yes. Quality of food will effect body odor. A lot of their body odor does go down. If say, you fed a very poor quality kibble diet, you'll get really stinky weasels and poops. The poops will be massive and really smelly. When fed on a raw/whole prey diet, it's a lot more 'cleansing' and doesn't contain 'bad stuff'. Their odor disappears to almost nothing. Ferrets produce a lot of body oils. The diet is reflected in those oils. The worse the diet, the more those oils smell. And vice versa.
And their poops are almost nonexistent. It's basically just the prey's fur that comes out.
But of course there will still be some ferrety odor. Just toned down by many times compared to a kibble fed ferret. I honestly cannot smell my ferrets any more. The odor of my friends' kibble fed ferrets are much much stronger.
Honestly, it depends on the individual. It is mostly true though. Most of the ferrets I've met have always done excellent in pairs or more. But there are the occasional loner ferrets who just can't stand other ferrets. I know three particular individuals who hate other ferrets and would rather just be alone with their human. But those ferrets tend to need more individual attention. In a group, the ferrets have at least each other to play with and keep each other company if you're ever too busy.
I would still recommend pairs or more to everyone though. I think 3 is the magic number. Ferrets tend to bond to each other, so when one passes, the other often goes into depression (no joke) and will often pass soon after as well. With 3 ferrets, if one passes, the other two will still have each other.
I personally have 3. My boyfriend has 3 of his own as well. Between the both of us, we've fostered a couple ferrets over time with our crew. All of those fosters have always appreciated the company of the other ferrets. And the crew has always coped better with the death of a group member or major changes in general when they were all together.
Yes. The are very cute. But be careful. They are A LOT of work and responsibility.