One of the main reasons I haven't switched over to a Jagex account is that last I checked, you would get only a set of backup codes and an authenticator app. I am honestly worried about losing one or both of these things. Are there any other mechanisms through which I could recover my account with?
The key to maintaining control of a new Jagex Account is keeping access to and control of the linked email.
The Authenticator you set up can be set up on a desktop, laptop, mobile phone or a USB stick. So you choose the setup that you feel will be the best for you.
The backup codes need to be recorded in a manner that will stay secure.
What happens if you lose one or both of these things?
If you lose one, you have the other to get you back on track.
If you lose both then you really, REALLY need to still have access to the linked email.
Go to the new Jagex Accounts Support Centre (linked at the top of the the old RuneScape Support Centre) and search
'Jagex account recovery'
as that page gives
all
the options for recovering a Jagex Account.
When I say
all
the options, I mean ALL the options.
Other methods of account recovery will not be available e.g. the old answer the questions about your account method.
I successfully created a Jagex account. I see an option to enable 2fa with my phone, however prior to registering for Jagex accounts I already had a 2fa on my main account. Do I need to create a new 2fa to receive codes for my Jagex account?
Yes, you will need to set a new Auth.
This is because you have set up a new account. The Jagex Account is not the same as your old RuneScape account.
You will be able to delete the old Auth off your phone (or wherever you have it). It doesn't need to be disabled through the website, just a straight out delete is all that is required.