Trying to switch to low growth/lower maintenance

I have a 55 gallon planted tank that I will be taking down to move to a new room in the near future, and I want to take the opportunity to try to make it over and have it easier to maintain in the process.

Here's some info on the tank as it stands now (tried to bold significant parts as I get long winded :icon_mrgr):
Lighting is Current Satellite 2x65W daylight pc, 10 hours a day
No CO2; I've been doing some EI-style dry fertilizers daily with Flourish Excel, but I've been getting lazy on this.
Plants: a couple dozen stems of Hygrophila salicifolia, 1 Crinum thaianum, about 6 Anubias of different species, several crypts (not exactly sure which species, they are all staying small and slow growing). The Hygro grows very fast -- I can trim and replant every 2 or 3 weeks. The Hygro and the anubias show yellowing of older leaves, presumably K deficiency, so I've increased potassium sulfate dosing.
Algae: For ~6 months there was only a modest amount of GSA on side glass (where I don't clean it) and on the Anubias leaves. I recently added ~18 olive nerite snails, and they have cleaned that up very well. More recently, older leaves of Hygro get a dark brown deposit that is hard to rub off (not fuzzy, just some surface deposit). The snails have been cleaning this as well, but there's a lot of leaves for them to cover. Also, leaves and driftwood in the filter outflow are starting to get BBA, I think.

Water: very hard and basic tapwater, ~40% change per week.

Tank inhabitants: 1 pearl gourami, 10 black neons, 5 penguin tetras, 6 kubotai loaches, 1 bristlenose pleco. (I know the water is not ideal for this set of fish, but they have acclimated and are healthy and happy, as far as I can tell.)
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My goals: To lower the maintenance on the tank, while still having a moderately attractive and healthy tank. Lower maintenance for me means, ideally:

1. Rarely trimming, and rarely or never replanting.
2. Only fertilizing at the weekly water change, if at all.
3. Weekly water changes are still expected.

Tentative plan: switching the substrate from chain store gravel over to something with more nutrients (and something loach-friendly), and getting rid of all the stem plants, focusing instead on crypt balansae for the background, and a bigger variety and number of Anubias, and then maybe one centerpiece plant like a sword of some kind. The idea being to have slower growing plants overall, getting more nutrients from the substrate. I will also be adding a lot of driftwood (there is some already), so planting area will be somewhat limited.

My questions:

1. What substrate would you recommend, bearing cost in mind? I was thinking of mixing a bag of Eco-complete with the Aquariumplants.com substrate (I've read the thread here).
2. My theory was that the Hygro was running through nutrients and starving the Anubias (and maybe the crypts I have; they don't show deficiency, but they grow even slower than Anubias, it seems... normal?)
3. If I get rid of the stems, will I be asking for algae outbreaks of some sort?
4. Should I switch one or both bulbs to 50/50? Changing to a new fixture is not desired.
5. I've read about BBA in high-flow areas coming from CO2 fluctuations. Any way to prevent this (other than supplementing CO2, of course)?

Ok, that's probably enough questions for now. Thanks if you read this far, and comments are appreciated!