You could always do the vest as a separate and then it would be there should it be needed. I made this jacket in denim that had a bit of stretch in it – didn’t realise until I was well into sewing.
It turned out beautifully but I didn’t do the vest at all because it doesn’t get below freezing here during the day. I would do the vest as a sort of windbreaker instead.
I think this would provide a challenge for you and teach you a few new things that are useful. It will show you a little more about pattern construction also and how linings work.
I encourage you to give it a go and take your time so that the process is not too overwhelming.
As for the scissors, I think they are just a bit of a guide as to the difficulty. This could be tackled by a semi beginner for sure because you would have the basics understood.
Tamara