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Aptos blue is a variety of sequoia (redwood) and grows up to 300' tall. Here's some information on them: http://selectree.calpoly.edu/tree-detail/sequoia-sempervirens-aptos-blue
I can't find any information on Soquel pines. Soquel is a park/forest in California, perhaps you've seen a pine variety marketed by some grower with that name. You would need to find out the true genus and specie for that plant to learn anything about it.

Here is an article that you may find helpful: https://www.gardeningknowhow.com/ornamental/trees/tgen/what-to-do-for-storm-damage-trees-repair.htm

I'm sure that, after 20 years, the somewhat acidic nature of soil beneath a pine tree has neutralized. I'm guessing you must have quite a bit of shade in this area. Here are some thoughts on growing grass in shady areas; https://www.gardeningknowhow.com/lawn-care/lgen/growing-grass-shade.htm
If you've already tried many different types of grass, you already know that trying to grow grass in an area that's too shady for it is an exercise in futility. You can of course create a nice mulched area, with nice flowing borders between the lawn and mulch. Or if you want plants, what a wonderful opportunity to create something much more interesting and beautiful than plain grass.
Here are some suggestions on what to grow in a shaded area: https://www.gardeningknowhow.com/special/shade/finding-a-shade-loving-plant.htm

First thing to think about is why the grass isn't growing in this spot. Since you have limed and applied new soil, and 20 years have passed, I think the acidifying effect of the pine tree has dissipated. Of course, you can always have a soil test done to determine the ph. You can have this done through the Extension Service; this link will help you locate one: https://www.gardeningknowhow.com/extension-search/
The main reasons grass doesn't grow in any given spot is that the spot is too shady, or too wet, has too much traffic, or something has been applied to the soil to inhibit growth. Since the pine tree grew there, I'm speculating that the spot is not too wet, so is it too shady? Have you tried grass adapted to relative shade? Or other ground cover options? This article discusses more on that: https://www.gardeningknowhow.com/lawn-care/lgen/growing-grass-shade.htm
Then, was anything applied to the area to kill the tree, perhaps, or the tree trunk? If so, you might not be able to grow anything there, and perhaps a mulched area with attractive flowing shape is an option. https://www.gardeningknowhow.com/garden-how-to/info/whats-the-best-mulch-for-my-garden.htm

If the spruce and pine are big at all, they will be casting shade, so one consideration is you need shade compatible plants. Another is that you need plants that prefer a somewhat acidic soil. You will also need plants that are hardy for your area. Then you will want to consider what kind of look you are after - groundcover, flowering annuals or perennials, evergreen or flowering bushes, seasonal or all year...the possibilities go on. Here are some suggestions to get you started: https://www.gardeningknowhow.com/special/shade/finding-a-shade-loving-plant.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/acid-loving-plants.htm

Many times the seeds can be harvested by gently shaking the cone once it's dried and from the tree. Or you can open the pine scales and then shake them out. Yes, you can put 2-3 seeds per pot and just thin out as needed, usually keeping the strongest.

If you haven't already read it, this article can help: https://www.gardeningknowhow.com/ornamental/trees/pine/how-to-grow-a-pine-tree-from-seed.htm