Couple of Questions Based on Articles Here

So, I have read couple of articles on Null Byte and I have some questions to it (maybe some will be stupid but i really want to know what do you think).

1. is question about staying anonymous on internet by using proxies...for example https://null-byte.wonderhowto.com/how-to/hacks-mr-robot-elliot-fsociety-made-their-hack-evil-corp-untraceable-0164294/
2. is question about TOR https://null-byte.wonderhowto.com/how-to/become-anonymous-internet-using-tor-0130391/
3. is question about ProtonMail https://null-byte.wonderhowto.com/how-to/hacks-mr-robot-send-ultra-secure-emails-0164676/

Questions:

1. If are these proxies free, also the other users are able to use them. Is here any way that they can add some bad script (sorry for this... question like an baby:D)? So i will be in danger?

And also I know there is some other way to setup my proxies in kali. It is in the right top banner. Is this ok or the method you used in tutorial was the only one and best. If I will set up my proxies in top right banner i don't need to run each program by typing in to the command, do I?

2. When I will be already running proxies I can still use TOR, right? Is this safe?

And should I run TOR by typing proxychains in to the command?

3. And last... also very stupid :). Is here some way how to get an email adress on ProtonMail without an telephone number?