hey! Some musical advice here! (I just watched the newest video about your guitar.)
While I don't play a classical - I play acoustic and electric, here's my advice: I don't know if it'd harm the guitar, it probably isn't the best?
And I usually use my fingers/thumb to strum. Try using your fingers instead of just your thumb (the thumb is used for the bass strings - low E and A)
I also use sixpence coins (yes, vintage British sixpence) but that's usually for my electric guitar. Maybe don't use a coin on a classical.
If you'd really like picks anyway, and can afford it, maybe try getting a ukulele? They're not super expensive (sometimes thrift stores have even cheaper ones), they're light, super easy to play (especially chords), portable, come in different sizes (for a baritone you do guitar chords, oddly enough, but the rest - concert, soprano, tenor - have their own uke chords.) I think part of my inspiration to play ukulele is George.. and a lot of his songs work well on ukulele. Much easier than on guitar.
About Norwegian Wood. Yes, it has a sitar on the studio recording, but it also has a 12-string guitar, which itself has a very sitar-like sound, if you were curious!