I have a candle lantern housed inside what I think is an aluminum frame. I'm concerned it will get hot enough to melt fabrics.
How can I safely use it inside a tent?
Should I suspend it from the tent ceiling somehow?
Is it safe to fall asleep with it lit?
You need a large tent if you want to have anything safely burning inside. The small, sleeping-only tent as most summer backpackers carry along won't do.
Nomads have been having fires in tents for aeons and aeons, and still do. They usually also forced pack animals to carry their stuff, for it was and is heavy. It is a matter of survival in cold climates. We today have (can afford) higher safety standards than in the past. You need a large tent. Your tent should have a chimney (opening at the top), so that any smoke and other exhaust gases can safely be expelled. There exist dedicated stoves with chimneys that connect through a tent roof. For an example of an enclosed stove, see Google Image Search for the Helsport Lavvu Stove. With such a chimney, a fire inside a dedicated stove is safe. However, that provides heating rather than light. Perhaps some models have a window so you can use the light and watch the fire?
Source: UK Campsite
For heating you would want a closed stove, but if your tent is sufficiently large and ventilated, people do make open fires too:
Source: discover the world
I imagine the tent in the picture may have the door open (perhaps the photographer is standing in the door), for this is part of a commercial tourist company so they won't want to take any risks. The reflected northern lights is edited in.
A candle lantern such as you describe should be substantially lower risk than the open fire in the picture described above. However, such tents are much heavier than the typical backpacker/trekking tent that summer hikers carry along. The solution is rather suitable for a winter base camp for a large group than for a lightweight summer/autumn hike. If you are winter trekking with a group of people in terrain suitable for pulling a sledge, you can carry a lot more gear than when relying on backpacks.
For a more modern family luxury alternative, I grew spending my summers camping in large tents like this, with petrol-powered lamps suspending from the ceiling or standing on a table. Us kids were told to be very careful around them, to not touch it and certainly not topple it, but I don't think they're really a big fire risk when handled carefully. Apparently, some companies market this as "glamping" nowadays, but I don't really see any difference from the vacations of my childhood. To answer your other question, we certainly never fell asleep with the lantern still switched on.
Source: tentfactory
For camping in a small backpacker's tent when you need light but not heat I would rather recommend battery-powered lights. Modern LEDs are very efficient so the weight of batteries you need to carry is really not that bad. For a solo trip where you must carry everything on your back, a good sleeping bag is probably the more sensible alternative.
Okay after some more research,
Don't leave it unattended (this would include sleeping).
Don't let it touch flammable materials.
Be careful touching it when its burning as you could burn yourself.
Suspending it looks like a good way to go, just remember not to bump it with your head.
