Vanilla strawberry will probably survive in that soil but it would be happier if you amended it with compost etc. It can handle afternoon sun especially if you make sure that the soil is nice and moist. Do not let it dry out. It is a paniculata, so it is much easier to deal with than the big leaf.

VS color not affected by soil ph so that doesn’t matter. Once established can handle full sun zone 5 no problem. Make sure to keep soil evenly moist especially first year. Definitely put 2-3 inches of straw mulch , it goes a long way

If you are going to amend, do not amend only the planting hole, especially in clay soil. You need to amend as large an area as possible, preferably the whole bed. That is because an amended hole in clay soil usually creates a “bathtub” where water from irrigation or rain fills the amended hole and then doesn’t drain away, causing the roots to rot. It is better to add amendments such as compost on top of clay soil if you cannot amend a really wide area. You can also plant a bit high and place the amendments mixed with native soil to create a bit of a mound around the upper part of the rootball that is higher than the soillevel. PH of 6.5 will make the plant happy. As others have said, keep your hydrangeas well mulched (though not directly against the stems) and the soil moist, not soggy for the first 1-3 years. After that, my panicled hydrangeas have needed no supplemental water, even in full sun and drought conditions. YMMV depending on your native soil and precipitation, but unlike your Bloomstruck, panicled hydrangeas like VS are happier on the drier side than wetter and don’t need a lot of extra moisture. Use the look of the foliage to decide if it is too dry once they have been there a few years.

As a side note, your Bloomstruck may shift to a more blue tone to the blossoms once the roots have reached into the native soil beyond the potting soil since your pH is slightly on the acid side, as long as the soil has some aluminum. Also it may need some winter protection to get spring blooms in zone 5 since the shrub as a whole is hardier than the flower buds or even the branches. My bigleafed hydrangeas like Bloomstruck often die back to the snow line so I don’t get flowers until late summer or fall on the new growth.

My VS is not newly planted but it does like to be moist. As soon as it gets on the drier side, leaves start getting brown on the edges and the next step is browning of flowers. Once that starts, those blossoms are gone and I need to really work on moisture to bring more for the fall. So try to get to know your plant and see what it likes!