I'm old school so I would suggest to learn to read music, tabs, and use your ears. Because you are using sheet music am I right in that you can read music? So maybe you already can read tabs?

I would take scenario #3 sans the input the bass lines and just play the song, mute the bass track, and record your actual bass as you read the score or tabs. If you can't read music use your ears and record your bass then listen to what you played, i.e. that is method us old guys had to do back in the days - play the record and copy our parts the best we could.

As a plus you can take your recorded base, convert it to MIDI, then see the actual notes you played all in BiaB.

Here are some sites that have free bass tabs:

https://www.guitarlobby.com/easy-bass-songs-for-beginners/

https://www.bigbasstabs.com/

https://www.songsterr.com/?inst=bass

I hope you find this helpful and good luck.

I phoned my wife and asked her if she wanted me to pickup fish and chips on the way home.
She just grunted.
She still regrets me naming the twins.

64 bit Win 10 Pro, the latest BiaB/RB, Roland Octa-Capture audio interface, a ton of software/hardware