at 4:42, qE(d1-d2) as E*d1=V1 , E*d2=V2 ,so eventually q(V1-V2). I was stuck here and found out the connection, like qE is force similar to mg is a force. Thanks sir.
At 3:30 the object "gains energy". Actually no energy is gained. It is converted from potential energy to kinetic energy. Maybe you meant to say it "gains kinetic energy"?
There are nice lectures here too with unified approach to electroststics and circuits Simple D.C. circuit. 1 Pattern of electric field. Watch from 16.0 minute. 2 Mechanical Battery Watch from 19.0 minute. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Eu3JQKrJRZA.htmlsi=t3MeX8Hi8ELAxaz0 3 First intro to Surface Charge Watch from 10.30 minute. 4 Surface charge gradient Watch from 15.30 minute. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-bp0o1HZOs3g.htmlsi=PPiPGepbXvdTgJHX