all in good time my friend.
you cannot speed up nature.
from my limited experience.......
forget the paintbrush for pollination.
take your finger, run it around the inside of the first flower and then go from flower to flower, pollinating as you go....

you will notice that the flowers may wilt and turn a brown colour.
this is a good sign. the chilli fruit will appear from there soon.
BTW your plants look totally fine IMO
let us know how they turn out.
cheers
