I have 3 crested geckos in a 25 gallon exo terra tank. 1 adult needs 20 gallons. Don't worry about the tail drop. From the pic I would say the gecko is a male and I have heard that males
tend to be more frisky. That is true for my adult male. Both of my males don't have tails and both of my females do. Eco earth is fine but if she wants to breed them in the future I wouldn't recomend it. I use paper towels for 2 reasons. 1 reason is that I don't want them to accidently get eco earth stuck in their throat and my 2nd reason is that I am breeding 3 of my 4 cresties. You can feed them some fruits once a month but not as their main diet. I feed my geckos crickets once in a while dusted with calcium without d3. For their main diet I use Repashy crested gecko diet. I feed mine every other night. I handle one of my gorls alot and she is fine with it. Some other people might have different opinions though. I think it all depends on the gecko. Some of my geckos don't tolerate handling alot and just go to the bathroom when I take them out, but those geckos are newer. I love my cresties, they are GREAT pets in my opinion. Don't let the temp in his cage get above 80 degrees f. Good luck! I would love to know how he is doing if your friend gets him.