@clyde That's right, edit 10 solved my initial query from the topic post, and edit 9 solved the second problem of poor wifi performance caused by wminput.
I think for most users who are trying to fix the latter issue, wminput -q -w would be perfectly acceptable. This way, wminput will keep searching (-w, waiting) for the Wiimote until it connects (clobbering wifi in the process). The "risk" here is that you can't find your Wiimote, or it's out of battery or something, so your Internet will go dead until you manage to get it synced. For me, when the entire network is relying on the Pi maintaining its connection, I'm better off with it timing out "just in case" the Wiimote isn't available, vs. the extra convenience of being able to connect any time after EmulationStation starts.
The biggest loss here is not being able to reconnect Wii Remotes after a disconnect, e.g. because of drained batteries, especially if it happens mid-game. Presumably you can SSH in and run attachwii again whenever you're ready to reconnect. Not terribly pretty, but for users who need their wifi up it's the best tradeoff I can see, short of changing how you handle your connections (e.g. wired internet, separate Bluetooth dongle, etc.)
There's probably a middle ground somewhere where you have a version of attachwii running in the background that periodically runs an hcitool scan and greps the result for your Wiimote, launching a wminput -q [-w] to reconnect if it finds it. Depending on how often you ran the scan it might not have the same devastating effect on your wifi, and it would otherwise be similar to running wminput -d, in terms of getting you (re)connected at arbitrary times. I'm just spitballing here though, I'm not sure how much impact hcitool scan has on wifi performance on a Pi 3 or other setups where BT/wifi interference is a major issue. For all I know, running hcitool scan constantly is just what wminput is doing behind the scenes that's causing all the problems.
EDIT: I also quickly threw together /home/pi/RetroPie/roms/ports/Attach Wiimote.sh:
#!/bin/bash
attachwii >/dev/null 2>&1
This can be run from the Ports menu in EmulationStation to sync the Wiimote without having to exit to command line to do it. It's of limited use, basically just if you forget to connect or get disconnected while you're in the EmulationStation menu. It's no help if you get disconnected mid-game, ssh is still the best option there currently.
