ALL SILVER AROWANAS ARE ABOUT 75% GUARANTEED TO GET DROP EYE! I've seen people on other forums ranting about thier silver's drop eye. They will all get it eventually. It doesn't make them a bad fish just cuz one of their eyes drops. They still look unique. All the silvers I see at my store have drop eye. To keep your silver from getting drop eye, it is nearly impossible. Some people suggested to my friend on another fourm that you should put a ping ball (forgot what it's called but my tooth hurts now and I'm about to pass out so I'm just guessing) to keep their head up or something like that.
As for them jumping out, it's their natural instinct to. They do it in the wild a lot. That's how they eat sometimes. They'll jump out for crickets, flies, worms, anything insect or bird if large enough. I think that's pretty unique in it'self. Although I don't have a tank big enough to house one, yet I plan on getting an arowana by 2020 when I have my own house and a big tank. In an Aquarium, yes the Arowana's jumping ablitly maybe decreased but they are still gonna get that jumping itch. The tank needs to be covered always. Even during water changes. I suggest to keep the water level as low as possible. If there are any flying insects near your tank, that can be a factor in jumping as well. Or it can be as simple as their gut instict telling them to jump.
I think you shouldn't give up on Silver Arowanas. They are a pretty cool and unique creature. They just need to be cared for properly and given a lot of attention to avoid them from jumping out.