First, we give NO requirements, in any form, for running FreeNAS in ESXi. We give some very heavy-handed recommendations, and you can still do all of those things and still lose your data.
Second, we make it *very very* clear that if you can't do those things it's exceedingly dangerous and you are very likely to not know until it's too late.
Now, we do not endorse or even remotely recommend running FreeNAS in a VM. If you do so it's at your own peril.
Third, as soon as we start saying "if you do this then do that and this and that" then people immediately start making the argument that we're endorsing FreeNAS in a VM. That's precisely what we are trying to avoid. We're very heavy-handed with this because we've literally seen dozens of users lose their pools suddenly and without warning. It has been considered more than once for putting together some kind of advanced/hacky guide for making FreeNAS work in a VM in the "safest" (if that is even possible). The problem... everyone things they are an advanced user, they always know better, and they won't lose their data. Why do you think we had dozens and dozens of users that lost their pools? Every one always said the same thing.. they were the exception and they knew better. Next thing they knew they were a statistic.
If you don't like this, that's fine. We're trying to do the best we can with what we have. And we can't (and don't) want to give the impression that virtualizing FreeNAS is a good idea. We've seen lots of lost data and we do NOT like the publicity that comes with someone else losing their pool every other day because they thought they knew better.
Just look at the stickies on how to virtuale. They are locked. Why are they locked? Because we've lost patience with people trying to make recommendations. People show up, throw a dozen or so posts on the forum (maybe provide a recommendation or two) and then promptly disappear. You don't see the dozens of posters that will take us adding info to make things work as our form of endorsement. It's not, and it never will be.
Now, if you want to stick around and tell every soul that shows up virtualizing and having problems with their jails how to setup promiscious mode, feel free. And they can be mad at *you* because you gave them the false sense that things aren't as dire as they actually are.
Remember, we don't even understand the mechanism for why virtualizing FreeNAS is so horrible. We just know it is from watching the dozens of users lose their pools.