Does it matter if a person has atrial flutter or atrial fibrillation?

Sure. While the immediate consequences of the knowledge may not be substantial (both can result in increased stroke risk and generally speaking patients with one heart risk for the other), isolated atrial flutter is often readily amenable to cure by catheter ablation procedures (85-98%). Atrial fibrillation is also amenable to such a procedure, though the success rates can be much lower (perhaps 70%).
Absolutely. Atrial fibrillation and atrial flutter can cause the heart to work poorly. This can create symptoms of chest pain, shortness of breath, palpitations, or dizziness. More importantly, in certain circumstances, these arrhythmias can cause strokes which are quite debilitating.
Depends. If a pt has chronic afib or flutter, their rate is well controlled, and they are well anticoagulated shouldnt be a problem especially if the pt is asymptomatic. If they have symptoms such as palpitations or shortness of breathe despite on a good medical program they need to be converted or ablated. Rate controll is important to avoid a cardiomyopathy and anticoagulation to prevent a stroke.