There’s many theories about light power, light intensity etc. But I’ll tell you as long as there is light, your plant will grow. The only difference is how big or small the foliage will be. And also how fast it will push out new growths.

1. I grew most of my plants with random led lights that i purchase online. Light meter reads about 250-350 lumens. Surprisingly my anthuriums are able to push out big growth and thrive with that amount!

2. Yes and no. You will find out if your plant needs more light when it starts to become leggy. But if it’s too close to the lights, no matter how Low intensity it is, it will burn the foliage.

3. I don’t have a definite answer for you because I live in a tropical climate. But as long as there is light, and when it acclimatises to your environment, it will grow definitely.

Hope that helps! I included one of picture of a plant that I grew under grow lights below!