Question on networking in Centos 7-7.1908

[Johan G]

Hi guys
I am a new comer in using centos-release-7-7.1908, I would like to ask following questions :
I am using nmtui and also I am editing the network configuration file ifcfg-ens224 in etc/sysconfig/network-scripts.
- Please advise whether it is possible to use both methods: nmtui and editing file ifcfg-ens224 , without conflicting each other?
- In case I edit ifcfg-ens224, will the changes be reflected if I open the device configuration using nmtui ?
- I saw in network-scripts, there are 2 (two) files ifcfg-ens224 and ifcfg-ens224-1 , why is ifcfg-ens224-1 being created and which process creating it? Note: I only created ifcfg-ens224. And Which one of the files will be used by the system network administration ?
- If I am using nmtui , how to set so that the route that I setup for that device will net be a default route.
- What are the effect in the system if there is more than one default route?
- If I configure the device using nmtui, is it possible to activate it using ifup and ifdown for that particular device , to avoid reset of the entire network?
Thanks for your advise.
Johan