Thanks for the quick reply Samuri! A helpful user on XDA suggested I reflash the stock radios, which I just did now, and it solved the Wifi problem!
But good to know that I can use House of Moto to flash FXZ 4.4 in case I ever need it.
About losing root, I did MotoWpNoMo and the first half SlapMyMoto before I took the OTA 4.4, so could I just apply the second part of SlapMyMoto after I flash 4.4 FXZ to get root back? Or does that only work if you're coming from the 12.15 Camera Update? If not, can you downgrade using House of Moto back to 12.15 Camera Update, and do it all over again? Thank you.