The manufacturer states the Timber Creek Enforcer AR-10 Oversized Ambidextrous Charging Handle will work with most AR10's. However, they do not specifically state it will work with the Remington R25. The Timber Creek Enforcer AR-10 Oversized Ambidextrous Charging Handle might work but fitment cannot be guaranteed. I recommend using the charging handle at the link below for that rifle.
https://www.opticsplanet.com/radian-weapons-raptor-ambidextrous-charging-handle-for-ar15-m16.html?_iv_gun-model=sr-25
Yes. All AR-10 charging handles are interchangeable.
No it doesn't. I got one today and tried to put it on my 716i and it does not fit. The front of the charging handle (the L shaped end) is not long enough to reach the bolt face and push the bolt back to unlock the lugs