Remove the burnt bits definitely. The flowers don't look far off being done, they haven't got large to the amount of light but should still give you some half decent medicine.
In terms of when to harvest them it's up to you, you could take them now and get new seeds going asap or wait another week or two, what are you thinking?
Honestly I'm not to sure.... I don't want them getting burnt anymore and now I'm working two jobs so that takes up A lot of my time.... I might try to wait one more week depending on how much damage that new light causes