There probably isn't going to be anything other than the sunflowers in your seed mix that you would want to grow. The round seeds you mention are most likely millet - that and anything else that germinates is going to be too weedy to have garden value.

The difference in bark texture is 100% natural. I've seen this thousands of times in most white oaks and Post Oaks, 100% normal. The bark natural peels like that, the thicker bark above will fall off usually in the next few decades and the smother parts will get rough again, this is a normal, very slow, natural cycle as the trunk grows larger in girth. All trees have there own unique way of bark peeling and flaking off as they stretch, crack, and grow new bark from underneath. Yes, that hole like thing is an injury. Something hit it around 5 to 10 years ago and make a gash in , and the wound is healing back nice. It will eventually close all the way up just fine if the tree is normal and healthy. That long line down the trunk does look like a lightning strike hit it many years ago (15 to 20 years ago), and the tree completely healed back over the bark wound. So no worries there. The only thing that worries me is it looks like the roots where covered in a layer of dirt looking at the trunk. Normally you should see a root flare (where the roots meet the trunk), but yours looks almost like a power pole. If most or whole entire area of the oak was recently covered in soil it may die within the next couple of years. But if it was just a very thin layer or just a small area no more than 1/3 of the root area or so, the tree might make it. Although very bad, some trees are more tolerant of compaction such as oaks, and they can slowly recover from a thin layer just fine but others just die quick, it's all dependant on the depth and area, if actually someone foolishly does this or does it from lack of knowledge on the topic. Though soil should never be allowed on the roots of a tree, roots need oxygen from the surface soil pores, if these are covered up good the tree will die from the lack of soil oxygen. That one big limb cut does look a little close to the trunk, but in time it will likely heal back fine. And remember one thing, Never allow a topped tree, this leads to decline and to hundreds of weakly attached shoots on the branches, you might as well cut the tree down if someone tops a tree, many eventually die a slow death from topping. If that was my tree I would wait to see how it looked in mid summer, if it looks like a normal oak then it probably will be fine, but if the tree crown is thin of leaves, and they are small, then it is declining, and will probably die.

Alternatively, if it's more convenient and you're not too squeamish, you can squash them by running your fingers and thumb (gently) up the stems and buds - makes one's fingers all greenish and interesting-smelling!! Check from time to time to see if any more have appeared, and repeat as necessary. :¬)

i dont understand if she is growing flowers or food?? i think you mean flowers .... but just checking ... otherwise.. yes.. as soon as a flower fades ... snip it off.. no need to waste energy on making seeds .. plants have one goal in life.. procreation ... and that means making a seed ... if allowed to go fully to seed.. most plants will stop blooming ... so you want to remove spent flowers as soon as they fade ... so the plant will make more flowers to try to make seed again ... make sense .. ken