Good to see you're forging ahead, so to speak!
If the cement you are using is the same as refractory cement here in the US (really a mortar for laying firebrick in fireplaces) then it is made with sodium silicate (water glass) and absolutely, it will burn your hands if you are using them as a trowel! Very alkaline (in fact made with sodium hydroxide -- lye). Get some rubber gloves to protect those hands for your nice machine work!
Also, cutting torches aren't good to aim at cement or concrete in general.
Probably best to plan all of your torch cutting in advance. But anyway, progress!
Sounds like you are going to go with a burner rather than a simple charcoal melter. I think charcoal is best for learning, and avoids some potential hazards, but I tend to go my own way, too, NeoTech, so I sympathize.
You won't need anything but the smallest of burners for this little furnace to melt aluminum, and maybe propane would be better than oil. That would be easier to control at first, and simpler.
Make sure your lining is thoroughly dried/cured, since it is so thick and applied so wet. then I would use a wood fire or even charcoal briquets to dry it out for 4 to 6 hours before even trying a burner in it. Take it very easy baking your lining or you will have lots of cracks and pops, and maybe splatters of lining out and about. No fun.
If your lining isn't similar to the fireplace mortar/cement I was talking about, but is in fact a true castable refractory, then things will probably go more smoothly -- since it is meant for the purpose and cures rather than dries. In that case follow all mfr's instructions. It's just hard to tell what you mean by cement.
I'm a big fan of the traditional fire clay and sand type linings, and hard firebrick, as you can probably tell.
Anyway, exciting to be on your way!
