Entertaining video, but I would not have guessed these speakers to cost over $14k. That's in the territory of the Bowers & Wilkins 804 D4 which is a substantially better made speaker:
Those should work well. The key thing about attaching speaker cables is to maintain the same orientation (red/black) for both left and right sides. Both the WiiM Amp and your Revel speakers are color-coded to make this foolproof. Enjoy!
Yes, you can see the two types at either end of the cables I linked. Your speakers appear to be able to accept either. Assuming the banana end fit into the WiiM amp, I'd connect the other end to speakers via spades. It will also work in the opposite orientation: spade end at the WiiM, bananas at...
It's a powered speaker with its own internal DAC circuits. You can attach a streamer to it via S/PDIF (coax, optical, or USB). You'd need a HDMI-to-S/PDIF adapter to connect an Apple TV.
If your Arcam processor has S/PDIF out, it can connect that way to the Meridian. If your speaker has analog...
Finding a PC with a digital input will be a challenge. Here's a PCI-E card that can do it:
Creative SB1040 Sound Blaster X-Fi Xtreme Audio PCI-E Sound Card
It seems the nature of these things that there is always "something I don't like" going on. That said, Daphile (LMS) is about as solid as it comes. The current issue with Daphile, though, is that it is stuck on an old version of LMS and shows no signs of being updated.
What issues are you having?