Anyone look into this?

Here's what I know (pls correct any errors):
1. Number of fat cells is determined by the time you reach adulthood . . .

2. Unless you gain a lot of weight in adulthood b/c each fat cell can only hold so much fat. If all the existing fat cells are getting full, the body produces new fat cells.

3. Fat cells are permanent. This sounds like bullshit to me. Cells die all the time, with the exception of things like nerve cells. If you lose the fat, why would the body keep around a bunch of unused fat cells forever (i.e., there must be some maintenance cost to upkeep the cell, and if it's not being used, seems to me the body would get rid of it). What I can buy is that unused fat cells stick around longer than unused muscle cells, as the latter have a higher maintenance cost.

4. Fat cells are highly variable in size, so if you lose the fat, having lots of empty fat cells won't make you look pudgy (bodybuilders are an example, though their blood chemistry is so altered, who knows if that's a relevant example).

5. Having more fat cells means it's easier to get fat. I.e., the more fat cells you have, the more readily your body stores fat. Might this be relevant to bulking strategies? Or do the benefits of relatively fast bulking outweigh any cons related to fat cell hyperplasia?