Will the paper scratch my emulsion (not a big issue going forward, I'll just leave the first frame blank)?
No, it won't scratch your emulsion, at least not on the part with the first frames.
Just leave the piece of card in the reel until you have the first several inches of film securely in the reel, then remove the card.
I think it might help you get the film started more quickly thereby reducing the amount of time you struggle and build up humidity in your bag.

Don't get frustrated as Paterson reels will work, good quality stainless reels like Hewes or Nikkor will work. It just takes practice and patience.
I can load a 120 reel in about a minute or two but I still struggle with 35mm when it is a 36 exposure, I hardly ever use 35mm so I don't worry about it.