No, it should only light up when you get close to the edges. Check the settings, I don’t recall anything to ‘always show’ but who knows… Worst comes to worst, you can reset and remake it pretty quick (which you do need to do occasionally as Quest still seems to forget sometimes). There are also advanced options for sensitivity.
As mentioned, just enable the experimental feature to add the recliner and it will show up as an outline in VR, and automatically switch to a stationary non-boundary mode when you sit there. Super feature!
Yes, you can have multiple boundaries, and Quest should switch between them automatically.
There’s also an experimental option to switch pass-through on when you leave a boundary, makes it easier to wander between them without removing the headset (or maybe this is default now, unsure)
You don’t need wireless on the desktop PC - if the PC is wired to the router, that’s probably better. As long as you have a decent modern Wifi, and Quest is not too far from it, it’s really easy to get going.