If your party is great, you don't need to waste dps by singing mana/tp too much or even at all. If the party starts whining for you losing dps over support, then maybe they need to manage their resources better so you don't have to support them as much.

The best parts to sing are whenever there's down-time to the actual fight. That way you can actually support without losing any dps at all. Sometimes you have to be flexible though, as parties are bad more often than they are great, and sometimes you may have to sing at unoptimal times.

Tbh I wouldn't worry too much if I were you. If you like Bard gameplay, just pick it up. Get critisised for your dps? Practice your rotations and priorities in fight and you'll get better. Learning to filter pointless banter from real critique is key.

At the end of the day you can be great at both dps and support. Dancing on that thin line between damage and support is what makes playing a bard really enjoyable.