Regarding the romance, it developed at the speed of sound for a shounen, though it is perhaps understandable since some parts have been left out, there is mutual attraction and flirting with death every day kinda does that to people (they tend to say some incredibly corny things).

Researching into memories, thoughts and feelings is an absolutely grand project that we're doing even today. Understanding how the brain works has so many great applications when you have the right regulations. Without lies we can solve every crime case, put fraudsters, and many politicians (maybe they are no different from the former) in jail. We can back up our memories and recover lost ones. We can help fight depression, and so many other things... Knowledge does not commit crimes, humans do. How we use it is up to us. Turning people into research subjects without their consent is bad, but since they don't remember anything after the fact and aren't directly harmed, the villain could have at least tried to appear a sympathetic martyr, accepting all kinds of condemnation for the sake of rapid progress (he'd grow old and die before people could agree on such matters, for example). Instead all he could say was that he wanted to be god blah blah blah. Tell me another story where 'science' doesn't try to overcome 'god', whatever that is.