Good question for beginners.

First of all: this rumor of a fork, I do not think will happen. The situation is way different than the one in 2017. Much complicated.

Q1: Yes, will be 2 distinctive chains.

Q2: Yes, you will have your BTC practically doubled, same amount on each chain, same private keys. That's why if you want to swap the "new coins" for more "old coins" you must do an operation using the private keys of each address and claim it on the new chain. That's why is recommended to move all your stash (old and new) to new addresses, because your private keys were exposed. If you do not claim new coins, your old stash is OK, no need to move it to new addresses.

Q3: yes

Q4: Usually who initiate the fork must rename their new chain. The original one is doing nothing so do not need to be renamed.

As an old bitcoiner, I've seen all Bitcoin forks (yes there were many in the past) and I would recommend to stick always with the original. Please read this important piece from the past, by Mircea Popescu: If you go on a Bitcoin fork, you will lose your Bitcoins and you will understand why. Only scammers wants to fork from original chain.

That's why I do not think this time will NOT be a fork. Is just a giant manipulation...

You have been warned.