Your Planted Tank
You've provided quite a lengthy list of issues. Here are some things I had to get right before my plants started to grow. Aquarium plants take quite some time to get used to tank conditions. Some never do, so patience is needed.
You must provide the right light, nutrients and pure water, large frequent water changes, for the plants and research their individual needs. Low light or shade plants aren't going to do well in strong light and the reverse is also true.
The Seachem liquid contains "Gluteraldehyde". Some plants don't tolerate it. There are a number of good liquids that don't have this industrial form of carbon.
Algae problems are typical of new tanks. The water chemistry isn't stable yet. Time is needed for the new plants, fish and water to work together to keep a level water chemistry. If there are too many nutrients (ferts) in the water, algae can be a problem. Keep feeding both fish and plants to a minimum. Your tank will be healthier.
Aquarium plants are tropical and used to long hours of daylight. It's been my experience, that tank lights need to be on at least 10 hours per day. Timers are helpful.
Just some thoughts to consider or not. Hope some of this is helpful.
"Fear not my child, just change the tank water."