Stevia and Spiders?

I plan to grow "stevia" on our patio which gets a lot of sun. The patio is on the first floor, overlooking the complex's garden. Once I saw a rat in the garden below, There are also a lot of spider webs in the garden. Would the "stevia" plant attract these creatures? If so, how can I protect the plants and myself from them?
I have been biten by spiders, just recently, and also in the past. This past month, my arm swelled up for over a six weeks after being bitten by a spider. The arm finally started to heal as a result of taking antibiotics.
1) Since "stevia" produces a sweetener, would this plant be more attractive to pests?

The intense sweetener is actually repellent to most animals. The only reason we like it is because we are smart enough to dry and powder it and then use it sparingly. If you were to eat it as is I guarantee you that after a few bites you would rinse your mouth rather than eat more!.

2) If so, what product can be used to repel them without poisoning the plant?

Spiders of course are not interested in eating the stevia, but the bugs that want to eat or suck from it. (It is amazing, but no matter what tastes a plant invents to be less palatable, some bug will evolve that is not impressed and eat it, or suck from it anyway. Of course if that were not so, such a plant would cover most of the world and replace everything else in the climatic conditions it can grow in.) To discourage spiders I can only suggest that you attract birds into your growing area. Also, if you see that egg packets that well fed spiders leave amongst their packaged victims, "squoosh" them while wearing rubber gloves- so that the mother spider can't bite you in defense of her offspring.
Be sure to have any bird food you put out in squirrel proof(and therefore rat proof) feeders, otherwise you attract them !!!

3) Is there such a thing as an ideal plant that grows tall and full along with being repugnant to pests?

One plant that I have never seen a pest on is ginkgo. I can't imagine that no animal or insect finds it palatable, but unlike such bug attracters as hibiscus it seems mostly pest free. Also the fewer chemicals you use the more predatory insects will be in your garden and the fewer pests will survive. Since predators are much fewer in number than their prey, they are the first to be eradicated when poisons are used.
Try growing thyme and oregano, both of which are not bothered by pests. Bees like the flowers, so don't get stung!