Dude.
Google. If I hadn't personally banned "let me google that for you" because it's such a jerk move, I would use it right now.
Google: Rapoo E6700 range. Right there, without even clicking "Enjoy long-range Bluetooth control from up to 10 meters (33 feet) away." I mean, it's from a product page, so not from actual people use and it absolutely would be a best case scenario, but I doubt there will be too many folks here with a Rapoo keyboard.
As far as working for BIOS, that one is murky. There seem to be reports of problems with BT keyboards in general
when googling that particular question. Worst case, if it doesn't work you can just plug in a wired keyboard on the hopefully rare occasion you need to get into BIOS.
Regarding interference, both WiFi and Bluetooth occupy the same frequency band, so there is a distinct possibility of interference. However, because of Bluetooth's frequency-hopping nature, the chance of direct interference is at least reduced if not eliminated totally. If you're interested in the matter,
HP has a layperson-friendly paper on it here.
EDIT - I'm sorry, I'm trying very hard not to be rude. Very. This is me being nice, responding as helpfully as I can. Sometimes you really just have to at least try to help yourself. In this instance, you could have answered all of your own questions very easily, hence the frustration. I'm sorry if you are offended by my post.