You might also add:
Too much of the wrong kind of spectrum as #4. If you have much of the typical white LEDs, you could be blasting the SPS with too much yellow, green and red.
I keep my alk at 9-10, but I don't get too concerned with ULNS... I let the Sandbed handle the nitrate and phosphate and both consistently test out "clear" on Salifert with no nuisance algae that the emeralds and snails cannot handle. ...the skimmer and coral take their part and the bacteria get to equilibrium on the rest.
Those are just frags. They don't even look encrusted yet. Give them some time before you do anything too crazy. They will grow quite fast if you are any good at this - I recently moved and started over with frags. For example, I got a Red Planet the size of a cheddar goldfish cracker in about February and it is the size of a normal sized cereal bowl 6 months later (about 6" across and 2.5" tall). I got a 1" frag of cali tort (the original ORA one) that is now 8" tall and 3-4" across. My RR multicolored matrix was the size of a M&M and now the size of a golf ball (pretty good for this coral). Anyway, have some patience with the SPS.
I have seen hundreds of high-end SPS tanks all across the nation and I have yet to see one with LED that I would trade mine for - even most of those that had LEDs will readily admit that their MH colored the SPS better, but they like LED for other reasons and were happy with their choice. A good part of the old-school have spent significant time and money with LED and will not switch yet - so they are not too dogmatic to give it a go. There are 2 tanks that I want to see the next time that I make it to San Jose for work that use LED. I know that you don't want a LED argument, or discussion or anything, so this is not my intention... my intention is to suggest that you consider keeping your expectations at a reasonable level if the main thing that you want out of your LED are to have really colorful acros. There are a lot of things to love about LED, so please make the colors just part of the overall experience.
Make some SPS friends locally. They will have different lights. You can trade frags and look at the same coral in different tanks.