how large a bore with a sleeved block?

There are several way to sleeve a block but I will describe two of them . the first is boring out the cylinder to the outside diameter of the sleeve . Put sleeve in the freezer for several hours to shrink it and pound it in with a block of wood and a B.F.H. The second one is a common one used in heavy duty diesels but is also used in Top fuel/Alcohol Hemi's. This sleeve is the bore on the inside and the water jacked on the outside . A tool (called a "sleeve puller") is used to remove the sleeve . A glorified slide hammer. There is a step at the top of the block to keep the sleeve from going too far down the hole . sometimes the sleeve has a flat at the top, also to keep it from rotating . I have pulled sleeves from stationary diesels that are the size of a 55 gallon drum . But that's for another time . So , to answer your question . the sleeve is limited by the head bolts and by the center to center distance of the bores .
Yes yes yes. The diesels have a counterbore and sealing rings to keep the coolant out of the combustion chamber on the top and bottom. Most have no water jackets. As I said earlier, those blocks are purposely designed for that kind of sleeve.