But @nc50lc is right, you don't need to add listen=0.
~Snipped~
Correct.
Yup. The setting is only disabled if you're running a proxy or through Tor.
~Snipped~
This is correct. It is good to be able to have inbound connection, for the network but it doesn't necessarily mean that you're not contributing to the network. Even if you do enable inbound connection, then the primary benefits should fall on you and the overall benefits on the network is secondary.
Thank you for all of the above confirmations
[I appreciate it] 
Are there any steps to enable portforwarding using your VPN?
Unfortunately, "
there's none".
If canyouseeme.org shows false, then the problem is with your portforwarding and not Core.
You're right... I found a workaround of some sort and I'll probably stick with it for the time being
[credit goes to this video]:
Note: It doesn't work with a VPN connection [if you try it, you need to restart your windows to get it back to work].- Steps:
- Download uTorrent
- Option > Preferences > Connections > Listening Port > 8333 > Apply > Ok.
- Keep it open!
I'll keep the thread open for now
[hopefully, there are still a few other things/solutions to try].