Theoretically - you can, since there’s a limited number of IP addresses (this is due to technical reasons, say, how the number of Bitcoins is also finite), and as a result, many people visit the same sites from the same IP addresses.
And when an online marketer connects from the same IP address, they blend in with the crowd. Meaning that you don’t HAVE to use different accounts from the same mobile IP address at the same time.
On the other hand, if your work involves using software with similar actions, then websites will quickly detect you, since identical actions are being carried out from a single IP address.
This means that if you uniqueize your actions in different accounts and don’t go overboard - you can, but it would be best to use a different IP address for each account, to be 100% safe.
Yes, you can, watch this video:
One mobile proxy will be quite enough.
For example, if you have an affiliate marketing team, we recommend each webmaster having their own phone (and proxy).