The literature on BAV disease seems to indicate that aneurysms can and do occur independently of valve stenosis/regurgitation...e.g., even after AVR. BAV disease is thought to be a connective tissue disease (like Marfans.)
I don't remember reading that more intense forms of exercise have been shown to exacerbate the formation of aneurysms. Recommendations for exercise seem to be based on the individual patient's situation. In my case, I was recently told not to lift more than 1/2 of my lean body weight, and that I can do any exercise that does not make me grunt or cause extreme fatigue. This comes from a top surgeon at a major university heart center (Bavaria/HUP).
Aneurysms develop because of weakened tissue in the walls of vessels due to genetic factors. However, once an aneurysm is present, then certain activities, like competative sports and weight lifting, should be avoided because of the risk of rupture or dissection, while other forms of exercise, like walking, are actually beneficial. Blood pressure control is the therapy for aneurysms.