Re: Attaching limbs to a torso?
I think it would help if you could upload your sculpture for the forum to advice you.
The decision to make a single mold or separate molds depend on allot of factors.
For me its important to consider what material you are going to cast your sculpture in.
If its bronze then you must keep in mind that it will most probably be cast hollow.(Thin small sculpture could be cast solid)
So a complex sculpture with limbs (depending on the size) will be easier to cast by separate molds for limbs and torso.
You need special equipment and some practice to re-assemble the sculpture afterwards. Some surface detail could be difficult to fix afterwards.
If you consider casting it solid (depending on the medium) then a single mold would probably be the best option.
Hope this helps.