I opened the files for the three new performing careers in S3pe and found some useful information. Here it is:
Singer
This is what it says in s3pe:
<kPositiveTraits value="Diva, SocialButterfly, Ambitious, NaturalBornPerformer, Charismatic, Virtuoso">
<!--Positive trait bonuses-->
</kPositiveTraits>
<kPositiveBonuses value="0.2, 0.1, 0.1, 0.3, 0.1, 0.25">
<!--Positive bonus percentage-->
</kPositiveBonuses>
<kNegativeTraits value="AbsentMinded, Clumsy, Coward, Loser">
<!--Negative trait bonuses-->
</kNegativeTraits>
<kNegativeBonuses value="-0.1, -0.2, -0.2, -0.2">
So, that means that the following traits gives bonuses to the Singer career:
Natural Born Performer .3
Virtuoso .25
Diva .2
Ambitious .1
Charismatic .1
Social Butterfly .1
The following traits give negative bonuses:
Clumsy -.2
Coward -.2
Loser -.2
Absent-minded -.1
Magician
Traits giving bonuses:
NaturalBornPerformer .3
Ambitious .2
Social Butterfly .2
Traits giving minuses:
Absent-minded -.2
Clumsy -.2
Coward -.2
Loser -.2
Acrobat
Traits giving bonuses:
Natural Born Performer .3
Athletic .2
Ambitious .1
Traits giving minuses:
Absent-minded -.2
Clumsy -.2
Coward -.2
Loser -.2
I don't know why it's not as bad to be an absent-minded singer as it is to be an absent-minded acrobat (you'd think forgetting the words would matter), and I don't know why it's a bigger advantage to be an ambitious magician than to be an ambitious singer or acrobat. But that's what the files say.
Happy simming!