Aloe is water based, so mixing aloe with oil directly is not going to make "aloe oil". The two ingredients will just separate out.
You could emulsify aloe gel with an oil -- in other words, make a lotion -- but you'd need an emulsifier and a preservative, as you are thinking.
The "aloe oil" I'm seeing on the market appears to be a different thing entirely from what I think you're proposing. One tute said to heat ground up aloe until all the water is driven off and the particles are browned. Other tutes show diced up aloe that's been cooked until the bits of aloe are dark, but not dry, which means some water is still present. I"m not sure I agree with these tutes entirely, because there's a real chance of microbial contamination when making an oil-based infusion with fresh vegetation.
Anyways, these tutes finish by instructing you to filter off all particles, leaving whatever remaining aloe chemicals that have become infused into the oil. At this point there should also be no water left either for safety's sake.
edit -- here's a more sensibile tute that follows the rules I've been taught for making safe infusions:
Why and How to Make Aloe Oil I would think you could use aloe powder for an infusion, rather than dehydrated aloe leaves.
Why do you think aloe powder will leave any more sediment than the aloe gel? The powder is dried aloe gel, isn't it?