1 - Maybe, but if he can, he would already do it anyway. Most of times, not.
It's a disarm attempt made from distance. Apart from the distance, all normal rules of Disarm still applies since you can't benefit from the feat Improved Disarm. However, you're 25ft away; unless your enemy can reach and threat this distance (i.e. Huge creature with a reach weapon) he can't make an AoO against you and if he can, he would already do because you're shooting while in his threatened area.
2 - Unlikely.
Unless the rare condition of an enemy with outstanding reach being the target of your attempt, there's no reason to even think about something like that. If the condition is true though, I think it's ridiculous but RAW he will be able to try to disarm you since you still can't benefit from the Improved Disarm feat.
My guess would be that the answers are "no" for both questions, but it seems a bit powerful (disarm with no AoO, and no consequences if it missed).
You paid a feat for it, you know? Improved Disarm also let you try to disarm someone without being retaliated and it is even more reliable.
PS: Either way, I really don't recommend trying to disarm two-handed reach weapons from huge or bigger enemies with your ranged weapon because they will have a lot of bonuses in their favour anyway and can reach you under 30ft.