Help with what looks like a greyish growth starting from the tips of leaves

I have been growing a superberry plant or something (not sure about seed origin) for nearly two and a half months. For the past month ive had it in a meter high grow tent with a 450w MH lamp (which i know is very silly) but it's been fine since ive lowered it with threads so its over 20cm away from the light. Since ive been feeding it with water for the past 5 days to start flushing it, some tips are burning brown at the top (first two pictures have some burnt leaves) and some leave have been going a moldy looking grey which ive tried to picture in the last photo but it didnt come out too well.

Should i cut all the effected leaves off? or just cut the grey moldy parts? What could i do to help my plant frost up as well? Just any help would be greatly appreciated please!

not really sure due to the pics.. needs better focusing.. looks to me like light-heat burn ?
If it's a mold you might be able to tell if you can rub the plant and spores come off... (will look like cig ash )

it's heat damage for sure - what temp has the plant been exposed to?

it was never higher than 28 Celsius until yesterday when it went to 33 Celsius. ive got it back down to 25, do you think that it could recover in just over a week? really worried that its not going to frost a great deal =[

Some of the tops of the buds are slightly crispy and have noticeably shorter trichomes.