This would not have worked correctly... Electrum seeds ARE NOT BIP39 compatible, with generally means that Electrum seeds ARE NOT COMPATIBLE with any other known wallet...
Is there any way that i can claim this BTG?

Yes, but it will need to be done manually... In your Electrum wallet, you need to go to your "Addresses" tab and look at ALL the addresses... receive and change... "used" and unused.
What you want to look for is all the addresses that you can find that has a non-zero "Tx" value... A non-zero "Tx" value means that the address MUST have received coins at some point:

Export the private key for EVERY address that has a non-zero TX value. Some of them may not have any BTG (as they might have been empty at the time of the fork), but if you export all of them, you're won't miss any coins

Don't forget to look through all your "change" as well as "receive" addresses... including both "used" and "unused".
Then you simply import all the private keys into the BTG wallet of your choice... and your BTG should show up 
Do you need to or would you advise sending out all the BTC from an address before importing it into some BTG wallet? Also, which BTG wallet do you recommend/use? The one from their official site was recently compromised (among other things wrong with BTG).
Anyway to do this "cold" like with Electron Cash
Don't want to risk putting private key inside an Android phone (which are always full of exploits) or on an online computer with the main wallet
Rather create the transaction and sign it offline
Maybe you can do it by using Bitcoin Gold core? The problem with BTG is that there are almost no working wallet available.
There is/was, you're just going to have to be willing to say "bye bye" to your BTC's during use.