I'm sorry about rolling my eyes. It's just that now it seems everyone has to walk on eggshells when it comes to certain topics. Sometimes it's just to much to keep up with what is correct and what is not. One of my dearest friends is black and gay and that's exactly how he refers to himself as. It's different for everybody so I hope you don't think I'm attacking you personally.
I used to spend lots of money on supplies. I don't now only because I am currently unemployed, but trust me, it kills me not being able to buy what I want.
Your safest bet is to use a FO (fragrance oil) made for candles. I wouldn't attempt the cologne. I'm sure someone will explain better why it's not safe to use cologne. hth
Do the tins get hot? Yes. About the other questions. Everybody will probably answer differently. It's mainly personal preference. Buy, try and see what you like is the only advice I can give you.