Ask Mr. Smarty Plants

We can't help you with your second question. Ficus carica is native to southwest Asia and the eastern Meditteranean area. The Lady Bird Johnson Wildflower Center is dedicated to the care, protection and propagation of plants native not only to North America but to the area in which the plants are being grown. We found an essortment website How to grow and care for a fig tree that might be of some use to you.

On the subject of getting rid of yucca plants, that's going to be difficult, because yuccas are tough desert native plants, and they resist being exterminated. However, you are not the only one who has wanted to either get rid of or thin out their existing yuccas. We don't know which species of  yucca  you have, but Yucca constricta (Buckley's yucca) is shown on the USDA Texas map as growing native around Blanco. Here is an excerpt from a previous Mr. Smarty Plants answer:

Members of the Genus Yucca are all similar enough that we can talk about them in general terms. You do have a problem getting rid of your unwanted plants. Yucca has a root you wouldn't believe, big and going deep. It propagates itself both by seed and by offshoots, or pups, from the main plant. The first thing is to avoid further propagation by seed. If your yuccas are blooming, get the blossom trunk down and disposed of before the seed pods turn dark brown. Then you can go on to the rest of the plant. 

There is no magic potion. You are going to have to arm yourself with heavy clothes, long leather gloves and goggles to protect your eyes from those stilleto-like leaves, as well as some serious cutting equipment. First, cut down as much as you can of the leaves, or blades, if you prefer. You probably already know that their edges are sharp, their tips are sharp, and they are tough. Begin with the offshoots and work your way in. Any piece of root left in the ground will sprout a new plant. Dispose of these cuttings in heavy paper bags (they'll rip plastic to shreds) and send them to the trash. Don't put them in the compost, or pile them somewhere, they stay lethal for a long time. Although we have no documentation to prove this will work, you might ask your nursery to recommend some herbicide that is meant to be painted on cut-off trunks to kill the roots. Cut the yuccas that you can't dig out down as close to the ground as possible, and then paint with the solution.You need to get the herbicide painted on the cut end within 5 minutes of cutting, as it will try to heal itself and keep the herbicide from circulating to damage the root. Don't get carried away, you don't want to contaminate the soil around the yucca, where you will presumably want to plant something else in the future. And don't spray! Spray can drift to other plants that you didn't intend to destroy, and probably do them more damage than the yucca.

You will have to continue destroying yuccas for some time. Don't let them get ahead of you, be vigilant to root out the offsets and destroy them before they get firmly entrenched. The yucca is a survivor, growing in some of the bleakest desert land in the country. There is one other remedy that has occurred to us-when you look up information on how to care for a yucca, you are always warned not to water it, not to let the roots stand in water, don't let it get wet. So, try flooding the roots and see if that helps. Never tried it, but it's cheaper than herbicide. 

Yucca constricta

Yucca constricta

Yucca constricta

Yucca constricta