yikes you like playin with fire, literaly. Building landmark pillars too tall is risky as you still need to find a way back down after the fact, higher you go the easier it is to screw up and die. adding lava to the mix just adds another layer of risk plus you need to cart all those lava buckets around while exploring. Well its safe enough in creative mode but then agian its alot easier to find a base agian from the air anyway as long as there are some visable landmarks and you didnt make the whole thing underground.