Regarding link saturation - have you tried tc/wondershaper? https://unix.stackexchange.com/questions/28198/how-to-limit-network-bandwidth#28203

Iptables commands - that was needed at the very launch of wg, I've not had to deal with it for some time now.

Personal/commercial use - I'm on a completely opposite side. It's perfect for personal use, but its lack of dhcp support makes me question its capability in a commercial setting. Many providers offer it, so clearly that's not an insurmountable task, but I'm still curious how they sort out their backend.