We did not used a painted/stained combo, but strictly stained. Disclaimer: We did not stain anything ourselves, but paid a finisher to do it before install. We used 'rustic' cherry stained quite dark for all our interior trim, including our wood handrails. Since the entire 1st floor minus office is 'rustic' Maple, Treads and risers are also Maple, stained the same dark color. Balusters are wrought iron. I would say on a scale of 1 to 10 (with 10 being the darkest stain possible before looking black) our cherry trim is probably a 7. Grain pattern is present but not overwhelming, it tends to be tighter on cherry than oak, hickory, or walnut. Our Cherry is not red-hued whatsoever, because its too dark. We had no issue with staining Maple, even though I have heard some on here mention it is impossible to stain Maple dark because it is such a hardwood. A good finisher will know what to do and should have no issues. I say 'rustic' because we requested wood with knots and such, to add more character and we wanted the cherry to match better with our knotty alder interior doors.

We want to paint the trim of the house a different color. We would also like to paint the deck rail a different color. The house is surrounded by redwoods.

I don't know about that. it's too much. you have the brown color of the deck, the black wrought iron, the brown stain of the railing, and now you want to throw in white? If you want the white, then just wait until you can replace the spindles. Or, redo the spindles like this. it shouldn't be that much to remove what you have and get these. In any case, keep it uniform. you don't want a railing w/3 different colors and elements. Or look into do the cable. you can DIY that and save quite a bit. The white w/the cables will look like this this is a white aluminum railing I'd forgo the white and do everything in black, like this Have you thought about just painting your railing black to match your spindles? maybe that's better. Or, paint like shown and just stain the top rail

I plan on painting the walls and trim of this room chantilly lace. I am replacing the brown doors with white modern ones. I will be painting the horizontal ceiling beam black. I also plan to extend the black paint up the post (conecting the two railings) and up the wall that connects to the ceiling. I need help with what color to paint to wood railings and the walls on the far side of the railings. I was thinking of doing the railing white and the walls behind a gray. Maybe smoke ember or nimbus. Help