Two Weeks into Flowering - Just a Few Concerns

Today was the 15th day of flowering for my grow, which is 5 plants under two 150 watt HPS bulbs and four 4' T5 florescents. This is a picture of my setup. I have the tubes angled on the side to help get light to the lower branches, since the plants are bigger than I anticipated and the small HPS bulbs don't have great penetration.

Anyway, everything is going OK but I wanted to ask a few things. One, does this look like heat damage? They're growing pretty face and I accidentally let the plants get to within a few inches of the HPS bulbs. I noticed that the same day I noticed the damage, so I figure they're connected. It's the first time I've noticed any browning that high up.

Second, and more concerning, is this. The lower leaves have been dying at a fairy constant rate. New small leaves will grow only to die again. I think this is from lack of light penetrating to the lower leaves, but I wanted to see what others thing. Is this cause for concern or part of the normal plant cycle? If it's the lighting, will the overall plant health continue to be OK?

There is also one fan leaf that is suffering from yellow/brown speckling. It's about halfway up the plant and, as far as I can tell, is the only such leaf.

Last question is about the cuttings I made just a couple of days after flowering. They're almost two weeks old now and I have no idea if they'll make it or not. I cut them off down near the main stalk, took off the bottom set of leaves, moistened them, coated them in rooting hormone (powder), and planted them straight into the cups you see in the pictures. They've been under a 250 watt CFL on 18/6 the entire time and have been watered/sprayed several times. So, will they make it? Where did I go wrong and what can I do to ensure my cuttings survive next time?

Edit: Just to give some more info, the soil is Miracle Gro (I know, I can hear your groans) moisture control mix, which is only different as far as I can tell in that it contains additional coconut husks to hold moisture. I'm also feeding with Miracle Gro tomato fertilizer (18-18-21) every other watering, which I just recently stepped up from half strength to full strength. I know everybody recommends Fox Farm, etc. but I just bought what was available near my house. The temp also gets pretty hot (about 90 degrees) for at least 4-5 hours of every day. If I were starting over I'd have the lights on at night, but as it stands I'm afraid of shocking the plants by swapping it. I'm hoping to ride it out for this grow. I already have a pretty strong fan circulating air, so I don't feel like there's much else I can do. How badly is/will this affect everything?

your plant looks very good. the burnt edges are not from light or heat stress, but rather point to nutritional problems.

from the color of the leaves and the nutrition you described, it sounds like it maybe too high on nitrogen (toxicity), locking up other elements which cause bottom leaf damage (which is in any case normal during flowering, even this early, but can and should be avoided, though it's hard to).

your fert is very strong, a full dosage sounds a bit harsh on me. are the spots on the edges new? if so, it's probably related to you upping to full strength recently. my advice is to flush your soil (always a good thing to do) with 3 times the volume of your pots water pH 6.5 (or different if your soil needs correction, check the runoff pH). After flushing, resume feeding as usual, but perhaps at less than full strength.

of course always mind pH, it's quite important.

90 is not THAT bad but will decrease yield. not worth switching to night lights I guess (perhaps others will disagree, might be worth to search for info about that), but try to use any other means you can.

good luck!