Here's what I was taught as a cm:
Tipping waiters/waitresses - acceptable and encouraged
Tipping housekeepers - not needed but very nice and acceptable
Tipping park cms (custodial who cleaned your table, attractions cm who backdoored you into Anna and Elsa, Merch you found the last SW mb band) - not done and will have to be refused by cm. However, they told us that if guest was super insistent we were supposed to accept it as a gracious cm.
And then turn the money into management.

As a "starving" cp, guess what I did? Let's just that my acts of kindness, and the guests generosity paid for some groceries! Expect to be refused though.
Note: artists, hair braiders, etc exist as separate from Disney and it's nice to tip them.