Is acquired hypermobility of joints worse than being born w hypermobile joints as far as stability, etc.?

Unusual. ' lax' joints ( multiple ) is very unusual in older adults unless: you were 'born' w/ them and just have recently been diagnosed or you have sustained injuries to your joints( esp. The knee) and your joint has become unstable ; or you have developed arthritis( 'knock - kneed") of your knee as you have aged and your knee joint and ligaments about them have become 'stretched ' and loose. See ors.Gl!
It depends... That's actually a difficult question to answer since the clinical presentation of congenital hypermobility varies widely. In general though (and separate from the more severe laxity related disorders, ie Marfans, osteogenesis imperfecta, etc), I would say that acquired hypermobility, say from trauma, probably places you more at risk of injury, instability, and long-term functional deficits.