Signal strength : Router vs Hub


I’m new to this forum, kindly assist me if you can as I have many questions…

I currently have a total of 10 sonoff devices , all Wi-Fi, (basic , dw2, inching relay ) connected to my ZTE MC 888 LTE router .

The problem is that the Inching relay (and some dw2 switches) are connected several metres away from the router and the signal reaching these swithes is very ,very weak.

I was thinking of buying the Sonoff hub to solve this.

Q1. Can all the Wi-Fi switches connect directly to the Sonoff hub (32 device/zigbee hub ) ?..does the hub support this OR is the hub meant only for zigbee switches ?..please confirm this ?

Q2. Does the Sonoff hub (32 device/zigbee) push out a much more stronger signal than the ZTE MC888 router ?..which device will have a greater range?

Q3. When pairing the hub to the router , do you only have to enter the router name and password once for the hub ?..or do you still have to enter the router password for all other switches individually?

Q4. If the Hub does work better than the router…suppose I decide at a bit later on to change the router to a different brand /model …which will now mean that I will have to pair the hub again with the New router…Do I still have to enter just once the new password/name of the router for the hub or will all the switches require new pairing with the hub again ?

Thank you for your advice in advance.