Velemman K4700 and Naim amps

Just joined this forum so apologies if this has been asked and answered before.
I have a Naim Uniti Nova, and PMC Twenty5 24i speakers. The Nova has reportedly in a couple of people’s experience put DC on it’s output and damaged the loudspeaker connected, and having had a Nait 3 that fried a speaker in the past I thought I’d go down the Velemann K7400 route as I really don’t want the hassle.
So my questions are thus…
Can I use 2 x kits run in bridge mode?
Can I run this from the mains direct rather than going inside the Nova and invalidating the 5 year warranty?
Can I run the ground (mass) to the mains earth instead of trying to connect the chassis?
And finally does anyone know if I need Resistors 23-26. I don’t know if the Naim has a symmetrical or asymmetrical power supply
Your help and patience would be most appreciated
Thank you