What is the difference between 抽 and 拔？
抽 從「手」，「由」聲，本義為引、拉。(the basic meaning is 'lead' ; 'pull')
拔 像用雙手拔取草木之形 (The original character looked like the form of pulling grass with both hand)

The basic meaning of 抽 is 'pull' (toward a direction)
The basic meaning of 拔 is to 'pluck' (拔草 pluck grass from the ground or 拔毛 pluck feather from a bird)
Since the motion of pull and pluck look similar, the two words are often used in similar way. You observation is correct, 拔 usually imply pull against resistance while 抽 doesn't imply anything in term of degree of resistance.
As you can see from your research, both character have other meanings that are not overlapped. The 'pull' meaning is overlapped but with subtle difference