There are many threads around complaining about tipping, and while I don't give them too much credence,(go ask your local street musician what percentage of people give tips and how much money they earned yesterday and you will probably be amazed at how lucrative it is in SWG) a couple minor tweaks to entertainers would be good for them.
When I start or stop watching a performer it gives me a message to that effect, when someone starts listening to me I only know cause I start getting xp. I think it would be nice to include a message to the entertainer that so and so is watching them. (Yes it makes sense IC as well since you start tapping your foot and clapping when you watch, it's not like your being subtle, but in crowded bars it can be hard to figure out who your fans are.
The more important suggestion would be to allow the entertainer to focus on one person, granting that one person an increased rate of battle fatigue healing, while all other spectators would suffer (for the duration of the special attention) from a reduced healing rate. For simplicity I would say double and half rate, but anything is going to give entertainers a little more contol over thier audience, and people who choose to be stingy can be ignored and never get the increased rate.
I think these suggestions would not harm game balance, they are not vastly overpowering, and I suspect they would be pretty simple changes to make, but it might keep a segment of the entertainer population form becoming disheartned with thier lot in life.