I agree. first grows are a great learning experience. I personally would just harvest now and start another run ASAP. She's not going to get any better or bigger at this point, and without using a loupe to check, the pistils look about 50-75% amber. Imo it's in the harvest window, and you really won't get much benefit by waiting say another week. The fact that you even finished says a lot, because you'd be surprised how many try their first time and don't even finish. You might Yield and ounce or 2 from the looks of it.
I'd start over with the new light as that surely is part of the core issue. It seems the stalk of the plant is extremely thin, and hence the resulting foliage emanating from it. You should never have to hold the main apex untopped stalk up with a yoyo or tie unless it is bearing a lots of weight from bud. I assume this is from the serious lack of light the plant wanted during flower. I've also seen stretching issues like this due to light leaks as well during the dark period. Also I'm curious, did you defoliate this plant at all? If you didn't, great. If you did, I'd hold off on any defoliation experiments until a couple more grows under your belt. You would had yielded even more had you not defoliated in this instance. If you didn't defoliate, then I'm pretty sure we're looking at just a light issue here.
As long as you didn't overfeed you shouldn't need to flush. However most people just give water the last week or 2 of flower depending on strain and that constitutes as a flush without having to think about "Do i flush?". If you didn't overfeed and are already giving just water week 8-9 then you don't need to worry about flushing imo. if you burnt her extra crispy and think it could be an artifact in the end product there are flushing agents that you can mix with water the last weeks of flower to make the roots leech even more nutrients out. Hope that helps.