0. LK99 is so obviously a fraud. They've been dicking around with this substance for 24 years.
1. some diseases will be possible to fix, like metabolic problems, but where structures are already formed in an adult organism this will be impossible. Like Autism. Go ahead, change every chromosome in every cell, the malformed brain structures will remain.
2. Sure there will be ignition, but the facilities will be wildly too expensive for commercial power.
3. will never happen with conventional computing hardware. Maybe if someone figures out how to grow actual neurons