Does an empty bitcoin.conf file cause my Bitcoin-core wallet to have a balance of 0?

what is normally in bitcoin-conf

It is normal for it to be empty (0 bytes).

It only has contents if you deliberately change the configuration.

[I am] not seeing transactions on my wallet.dat type file [which was] opened and synced to the blockchain

If the blockchain is not fully synced you will see the “catching-up” icon at bottom right of the bitcoin-qt window:

If you have upgraded Bitcoin-core, you should check that a copy of your old wallet.dat is in the place expected by bitcoin-core. For example, in Windows 10 a default location would be %AppData%\Roaming\Bitcoin\wallets

is [there] a link [between] bitcoin.conf = 0 bytes AND not seeing transactions on my wallet

No.

In ordinary use of Bitcoin core, there is no link between these two observations.

If you had previously changed the bitcoin.conf to relocate wallet.dat when using an older version of Bitcoin core but did not follow a normal upgrade process that preserves bitcoin.conf then there could be a causative link. I would check one of my backups to see the previous contents of bitcoin.conf.

Also see