How can I make him/her happier

I am caring for a six year old spotted salamander. I feed him crickets with calcium and vitamin
powder coated so he gets some minerals and vitamins at least on the first one he eats, the others
it comes off of by the time he gets to them. He comes out and is not shy with me anymore. He had
two friends that died a couple years ago. Another yellow spotted and one blue spotted. I had moved
in with my girlfriend and maybe it was the different environment that caused the water to evaporate
faster than normal. The blue spotted died of dehydration, and the yellow spotted was injured when I
was cleaning the tank. I was very sad to loose them, but I can't imagine the trauma he went through.
Kept in a cage since birth and only two friends, both who died at about three and a half years of age.
I talked to him often apologizing for my negligence, and if I had it all to do over again, I wouldn't have
taken him from the wild by buying him as a new hatch-ling...knowing it is not recommended to reintroduce
captive living salamanders to the wild because of germ contamination risks to the local populations.
Funny, after I started talking to him, that's when he started coming out more and looking at me more.
I think these guys are psychic.
It just makes me sad to have a roaming type creature captive all his life.
I keep his tank at 67-69 average, and dark with places to hide. What do you think? Is there a way
to improve his captivation? I have never introduced formal lighting because it is not recommended
for mole salamanders, so no possibility of live moss terrarium with plants, as this also might make the
environment too warm.

Happier - no. If you are asking about appropriate care that will produce a healthy salamander, pay attention to substrate composition and moisture, clean environment, habitat with hides, proper temps and good ventilation and a well-balanced diet. Have you read the caresheets in caudata culture (the tiger caresheet is applicable to spotteds) and articles on substrates, foods, etc? A well cared for caudate can have a very long healthy life in captivity.