Seachem Flourish complete and Trace

[Oliverpool]

I just purchased the Flourish range of products such as Iron, Phosphate, Nitrogen, Flourish Complete and Excel. I still have a bottle of ADA Brighty K which is for potassium. I have a CO2 tank which currently runs my tank close to 20-30ppm from a drop checker (dark green). It runs for 8 hours together with my lights which I would say is medium light. My tank is only 6G but is heavily planted with mainly slow growing plants like hairgrass, annubias nana, Staurogyne sp, and fissiden. I have some Hortworth which is really the only fast growing plant. After some explosive growth, my plants and pearling seems to have tapered off. I am starting to get some pin holes and even yellow in the middle of old leaves in my annubias and staurogyne. A few of my Staurogyne melted away. Strangely around the time I introduced purigen into my system I put in the 100ml pack and maybe it was too much. My water was super clear and looked almost too clean. I have since took out the Purigen and left only around 20% in my hob filter. My water perimeters are as follows.

PH - 6.5-6.8
KH - 1 at the moment. My tap water is very soft and I have been adding Baking Powder a little when I do water change
GH - 4 - Again my tap water. Been adding Equalibrum and Prime during water change to keep this up (I am a Seachem fan as you can see)
Phosphate - Almost 0mg/l as tested this morning
ADA Amazonia soil in this tank which is around 2 months old.

I been dosing ADA Brighty K at 1ML every day as per their intructions (understand thats around 3.75ppm) when I searched on the web.

Not much algae problem except for slight BBA on some strands of hairgrass and some green algae growth on a bogwood in the center.

1. Can I safely dose Excel at 2.5ml day 1 with 0.5ml for next 5 days even with my CO2 running?

2. Can I combine equal amounts of iron and Excel in a pre-mixed bottle and does 1ML (0.5ml iron & 0.5ml excel) daily instead?

3. Can I do without flourish trace and just use complete? Too many bottles already :-p What should I increase my floruish complete amount to then?

4. Can I combine phosphate and nitrogen in a premix bottle and does 0.6ml on day 1 and 4 (0.3ml + 0.3ml) instead?

5. For potassium, I would like to finish using my ADA Brighty K. Can you advice me if I should just proceed with the ADA daily dosage or can I put 2 ml on the days that seachem recommends? (day 3 and 5)

I think thats all I have!! Thanks!