Disclosure, WYSIWYG and closed lists.

Interesting discussion here. My preferred style is to, as you said, say "here's a unit of khorne warriors with hand weapon and shield, standard and musician." I do not like to disclose magic banners, runes, fanatics, etc.

In the liche priest example, I would not worry about a lack of cloak on the model as I feel like they all have pouches and stuff on them and there could be some gear tucked away. I am particular, though, about things like lances. If my captasus model has a lance modeled, he will always be equipped with a lance, even when a magic sword suits him better. My only exception here is unit champions. I have no problem with my blood knight champ holding a sword but fighting with lance when I get into combat. I prefer my champs to be armed a little different as it helps them stand out.

I'm struggling right now as I build my unit of chaos goblins. There are a few models with spears, a few holding a hand weapon. What I might do here is something new for me:

I'm thinking about making a few 40mm unit fillers to represent shields or spears. Like a bucket of spears or a pile of shields. This is not ideal for me but the models I've sourced are armed with a variety of weapons. Would anyone have an issue with this?

As for the magic carpet, yeah I'd like to see something on the model to represent flight. Even if the guy had wings or a crude rocket strapped to his back, I'd prefer that to just telling me he could fly. An exception here is Daemonic and Vampire models. It's been discussed around the gaming table before that these characters don't really need wings modeled because it's plausible that a demon or vampire could just launch himself a great distance or even fly using some demonic or magical ability.

We play pretty much the way you're describing, but we don't do WYSIWYG. We also tend to play 2500+ point games and a lot of my friends don't have that much money to spend on every representation of models that they want to play with, so WYSIWYG only restricts our play.

Now, if you take magical items, we play so that you don't have to disclose those until you use them, but we also have lists of our armies, point values and their equipment to hand to each other before the game, but we don't take a look at them until after we've played. It's just a way of keeping each other honest. Also, if we get into a combat and someone reveals a magical item that significantly swings things in their favor, then we can always say, "No, really, I DO have it! Just check my list!"

We do, however, tell each other things like, "This is my general" or "This is my caster and he's a Lv4."

I am on the same page with everybody else, WYSIWIG for mundane equipment (loosely so not to get in the way, e.g. champions often have different weapons to stand out, only front rank has 'right' weapons for plain $$$ reasons). Magic items do not need to be represented, although cool points if they are, I've seen some pretty fun 'scroll caddy' conversions. The carpet also screams for a dedicated awesome model.

Tournament standard was open lists and locally that has seeped into pick-up games...regrettably so.

That's half the fun isn't it. Makes list building more thoughtful and not so cookie-cuttery. You can try out new surprise combos which are perhaps not optimal

We tend to play open lists at the club (and always for the comps) but not always for friendlies. Part of the effectiveness of a Dwarf ambush list is gone if they know it's coming. Open lists allow you to proxy (within reason) if needed and is a bit more friendly. I prefer closed lists for more competitive games.
I know what you mean about the magic carpet and it's one of the reasons I've converted my doombull. As soon as it's your first go, your opponent will likely know you have it (unless you are being particularly sneaky).

But you'd know it was a dragon though 

Greg