Goldenseal Growing On My Balcony!

A goldenseal plant is growing in a (somewhat large) flowerpot on my balcony. I'm delighted but I need to know how to protect it from the heat and the hot sun (Virginia, USA, North-East location) - it can get up to 100 degrees Fahrenheit on my balcony. Right now I have camo netting on the balcony fence which helps cut down on the sun light somewhat, but not the heat.
Should I bring the plant indoors? It is about 2 feet (60cm) high already, which I think may be "spindly" for a goldenseal plant, if I am not mistaken. I have staked it securely so it does not bend and break from the wind.
Can I prune it? Will pruning affect the root development?
Are Goldenseal plants susceptible to aphid infestation? White flies?

Mature goldenseal plants do get to be as tall as your plant, but it is the sturdiness of the growth that is important not how tall it is. If your potting soil is rich the plant will get much taller than it would in a forest, even if it is sturdy. Check the thickness of the stem and the length of the stem distance between successive leaves. If that seems thin and long, then your plant is not getting enough light.
I think under your blazing light and heat conditions, the forest shade loving goldenseal would be better off indoors. Give it the brightest spot out of the hot sun that you can provide and watch the stem to see if you may have to supplement the light with fluorescent lights. Put the pot onto a pebble tray with water under the pot to increase the local humidity. In the winter keep the plant close to freezing and drier. On the balcony, the temperature would probably get too cold for the roots, since there is no ground-heat to keep the roots as warm as they would be sunk in a forest floor.
Pruning would reduce the strength of the plant because fewer leaves remain to make food -to be stored in the root.
We have never had aphid or white fly problems during the short time we keep goldenseal plants indoors. However if the plant is very etiolated (spindly) it would become far more attractive to pests. However, both pests are quickly controlled with a neem oil spray at the rate of two teaspoons of neem oil, plus one teaspoon of dishwash detergent in a litre (quart) of water.