Can Artisan work as a performance skill
Yes
In 4th edition "
The Artisan skill represents a number of different creative skills, including singing. (SR4 p. 126 Technical Skills - Artisan)
For using the Artisan skill as a social skill to perform in front of an audience rather as a technical skill to create or compose I would personally consider linking it to Charisma rather than Intuition.
is it okay to have perform be a custom skill?
Yes
In 5th edition there was an Artisan skill (linked to Intuition) and a separate Performance skill (linked to Charisma and part of the Acting skill group together with skills such as Con and Impersonation).
In 6th edition Artisan is not explicitly spelled out, instead there is a generic Engineering skill (could see a Artisan specialization here that would likely be linked to Intuition) and a separate generic Con skill (linked to Charisma which include specializations such as Acting, Disguise, Impersonating and also Performance).