1)Sunlight from 6 until 8 isn't of the best quality and the remaining 3 hours may not be enough?. If you can get it another 1-2 hours of sun, that should be better. Try it in your chosen spot & move it in 2 or 3 years if needed.

2)It's not very tall, plant it where it can be enjoyed and not crowded out. The leaves are wispy but the stems are typical peony.

3)It will probably bloom in 1-3 years depending on how ideal your growing conditions are.

4)Sounds good, top dress the compost in the fall, but not too thick over the crown (1" max)

5)Your preference...

Unlike P. lactiflora hybrids, P. tenuifolia is not a drought tolerant peony. It will perform better, retain foliage longer, and flower more, if you keep it irrigated during summer dry spells.

My plants get about 8 hours of fairly good sunshine a day. Sun has to get above the house, then sun lasts most of the rest of the day. Some dappled shade for the last couple hours as sun sets thru the tree.

In fact, my fernleaf peonies both opened today! They are quite pretty, being doubles, dark red. I have had pretty good luck with mine, since they have bloomed from the first year after planting. Have gotten thicker foliage, more blooms each season. Actually I find the coming buds on growing stems, to be the cutest part. Leaves are so fringed, the buds look like little Russian fur hats! I think my plants are now about 4 years old, from some pretty scrawny roots.

I would look at a more sunny location than you planned on. Hope the plant does well for you.