That is correct, however, to "cash out" the bitcoin gold without compromising your paper wallet you'll have to jump trough several hoops.
If you ever decide to "cash out" the bitcoin gold, it might be a good idear to sweep the paper wallet into a different bitcoin wallet, wait untill the sweeping transaction has confirmed, and afterwards (and only afterwards) import the private key from your paper wallet into a bitcoin gold compatible wallet.

As soon as your private key is entered in either wallet, your paper wallet must be marked as compromised. As soon as the bitcoin and bitcoin gold are spent, discard and never re-use the paper wallet again... Instead, making a new paper wallet to transfer your BTC to might be a good idear.

Yes, If you use Bitcoin paper wallet you can still receive an equal amount of Bitcoin Gold of your total Bitcoin holdings as long as you have your private key. After the hard fork, to be able to access it you will need to sweep your private key (which are printed on your paper wallet) in a Bitcoin Gold wallet that supports it, Coinomi and Electrum wallet lets you sweep private key but I don't know if Electrum will support it or just wait for some announcement on how you can access your free Bitcoin Gold.

Thanks for the explanation. But is this process affecting in any way the legacy block chain?

Let's suppose I have 1 BTC in bitcoin core address 'A'. I keep it until block number 491407 (bitcoin gold fork).
After this passed (let's say after 6 blocks in about 1 hour), I transfer out the 1 BTC to another address I own 'B'. After this is done, I will get the private key of 'A' address and store it so if needed, I can claim the 1 BTG using this private key.

First question:
- since replay protection is not implemented (at least no information about this), are there any risks of sending out the 1 BTC to another address 1 hour after the fork? Is there any risk of loosing the 1 BTC?
Second question:
- when and if I will import the 'A' address private key to a BTG wallet are there any risks? Is there a possibility that I will not get the 1 BTG? Or is it affecting somehow the already sent out 1 BTC to my 'B' address?

Thanks for the clarifications in advance.

Well, let's start from the bitcoin point of view.
You funded your paper wallet's address A. It has one unspent output in the UTXO set before the fork.
After the fork happened, you create a transaction that funds address B, using the unspent outputs from A (and signed with the pk on your paper wallet) and wait untill said transaction is confirmed.

At this point, address B is funded. No risks (if you used a clean PC and took all usual precautions you normally take when sweeping paper wallets).

Now, let's look at the bitcoin gold (from now on, i'll say BCG) point of view: what happens AFTER you broadcasted the above transaction on the bitcoin network.
There are 2 possibility's:

• either the transaction that was broadcasted on the bitcoin network is replayed on the BCG network, either by accident, by design or by someone bad. In this case, you end up with the same situation where you started from: you have a private key/public key/address (address B, since all unspent outputs for A would have been spent: on the bitcoin network they were spent by you, on the BCG network they were spent by the replay attack) that is valid on BCG and bitcoin network, and the address is funded. You have  to start over. If people keep replaying bitcoin transactions on the BCG network, you'll be stuck in a loop
• OR, the transaction was not broadcasted on the BCG network, you are now free to import the private key for address A into a BCG wallet. There are no unspent outputs in bitcoin's UTXO that can be spend on the bitcoin network, but there are unspent outputs on the BCG network, so you can now safely spend them without risks for a replay attack. If you spend BCG unspent outputs to address A by funding address C, and somebody tried to replay this transaction, it wouldn't work, since on the bitcoin network those unspent outputs would not be in the UTXO set, since they were used to fund address B. The replaying transaction on the bitcoin network would be invalid

So to summarize. If after fork, I send out the 1 BTC to another address 'B', my BTC can not be compromised anyway. Even if later I claim the 1 free BTG using my private key from address 'A'. Right?
However, after I import private key of 'A' address to a BTG wallet, it is possible that I won't see the 1 BTG because it has been replayed and already sent to address 'B', right?

Is it safe to declare that if you import to BTG a private key of a BTC wallet that has no funds on it, your BTC will always be safe, the only risk is with your BTG funds?

Yes, but you have to ask yourself if it's worth the trouble to compromise your cold storage (and the privacy thereof) to get this altcoin airdrop. The developer team comes off quite pathetic; they are pre-mining the chain. That's why it's not a "fork" in the sense of "update" but it's rather just a snapshot of the blockchain underlying a new altcoin.

The developers haven't been able to add replay protection successfully thus far (there is an open bounty for it with payment coming from the pre-mine), which doesn't bode well for the project. I'm guessing there will be a quick spike in price when it launches due to initial illiquidity, but long term I think project is dead in the water.

Well, at least, they have pumped up BTC price with the high demand, caused by the rush for BTC to get the BTG after the fork... Poor alts, they're suffering, but at least, we can buy them back cheaper in the very minute the fork has happened and people has not started to diversify their BTC again into the alts
To be on topic: The above mentioned advices should stand for all the forks, despite of the new alts has replay protection or not, just to be on the safe side.

You can also avail of the BTC Gold as long as you have the key to your paper wallet. But there just some complications since you need to follow the rules of the  fork. If you have read the rules then you are good to go but if you are tired of reading and wanted to play safe you can deposit your bitcoin to yobit or any of the exchanges that support bitcoin gold before the fork. Then after the fork you can just return it again to your paper wallet for safe keeping.

You can but you need to be really careful, especially if they dont go through with the level of replay protection they are claiming. Dont risk all your coins for a 2% boost.