I'm pretty new to gardening so this might be an all over the place set of questions.

I've been trying my hand at "upside down"/hanging tomato plants but I am limited with the amount of sunlight I can get because I live in an apartment building with limited space outside.

I've been doing a kind of experiment with three different tomato plants.

1 plant: in complete, regular sun

1 plant: in the shade with sun provided by a "Sunflower Home Heliostat" (it's basically a mirror that has a sun tracker so it can provide consistent sunlight to my tomato plant)

1 plant: gets afternoon sun but is otherwise in the shade

What I've found is the regular sun and mirror plant have flowered at about the same rate, and the fruit itself has grown at about the same rate -- but the mirror ones are actually bit larger. I'm not sure if this is due to the more consistent sunlight or if it might have to do with, maybe, the amount of fertilizer the plants are receiving (the one with the mirror is farther away from my building so it doesnt have runoff from the roof pouring through it in the rain... which could be washing away fertilizer or something), or maybe even pollination for the plants, because they're in a slightly different locations so maybe the access to them by bees or something varies enough? Maybe I'm just over thinking things... And then the plant that only gets afternoon sun, I've been struggling with overall.

I guess I'm just wondering if anyone has any thoughts on:

1. how much sunlight tomato plants actually need

2. how much fertilizer should I be using? if anything?

3. do I need to pollinate the plants myself somehow?

4. using mirrors to increase sunlight to plants in general and on tomatoes specifically - is this good, bad, effective?

And just if any experienced tomato growers might have any explanations as to the results I've been experiencing.

I'd appreciate any thoughts/explanations/comments. Thank you!!