Help with new planted tank please

[GreenTank1]

I started researching planted tanks about 6 months ago and decided I was ready to jump in. Well, I am not so sure now. It seems I cannot do anything to make my tank flourish. I planted the plants 3 weeks ago and while most of the plants that remain show new growth, the original parts of the plants are all still decaying and I am replanting plants 2-3 times per week that have detached from the rooted parts of the plants. I managed to keep at least one of every plant that I purchased, but some look to be on their last leg.

Tank Setup (fully cycled 3 months before putting current plants in, but no fish yet):
- 55 Gal Standard Tank
- 6x T-2 6400k lights (I've been told it is roughly equivalent to 3 T-5 54W lights)
-- 8 hours of light per day
- Eco Complete substrate (3" in front to 6" in back)
- EI dosing with CSM+B and GH booster, also have API root tabs for now and clay balls with CSM+B in substrate. Have osmicote plus that will go in after the current root tabs are done. I will soon start adding Iron to the regular water column dosing as well.
- 50% water change every week
- Pressurized CO2 with Cerges reactor where drop checker reads green by the time lights turn on...I had it reading yellow for a while, but am trying to dial back to allow fish eventually
-- CO2 starts 2 hours before lights turn on and stops 1 hour before lights out
- Rena XP3 filter and Hydor 750 for water flow

Water Parameters for what I can test:
- Ammonia/Nitrites = 0
- Nitrates = ~80 (day before 50% water change)
- PH drops about 1 degree during day due to CO2, but reads around 7.4 before CO2 added
- GH = 6
- KH = 4

Plants in tank (almost all arrived in great shape):
- Rotala roundifolia
- Myriophyllum sp. 'mini'
- Ludwidgia sp. 'red'
- Echinodorus tenelus (Sag?)
- Rotala Magenta
- Blyxa Japonica
- Ludwidgia repens x arcuata
- Water Sprite
- Proserpinaca palustris
- Limnophila macrandra

Video of my tank:
http://www.youtube.com/watch?v=kFEidIYBuX0

Still pictures if you do not prefer the video (sorry some of them are a little blurry as this was taken with my phone and the plants may be moving too much inside the tank to get a good still shot):
http://s1326.beta.photobucket.com/us...9%20Jan%202013

So questions I have:
1. Should I cut the new growth and replant for those plants that have a large amount of decaying in the old growth?
2. Are the plants telling me I don't have enough or too much light?
3. Do I need to adjust my EI dosing? I am sure I am going overboard, but that is kind of what it is about anyways right?
4. Do I have too much water flow? Is there enough/too much surface ripple? I am seeing some film on the surface.

Thank you for your help.