Q.Sago palm transplanting
When I transplant, how much of the bulb do I leave above the dirt, or bury it all?
The sago (which is not a palm of any kind, of course,) doesn't grow from a bulb, but from roots, same as any plant. You can bury part of it in the ground; also, if you've cut it from the mother plant, you can allow the pup to harden off for a couple of days, then bury the cut portion in the soil. Here are a couple of articles to help you understand the process. The first is a more condensed article: https://www.gardeningknowhow.com/ornamental/trees/palms-trees/propagate-palm-pups.htm
The second in much longer and more involved: http://www.rhapisgardens.com/sagos/sagopups.htm