As long as it is architectural or house paint, you can use it in a bathroom. However, an exterior grade paint will not wash or scrub as well as a paint formulated for interior use so a 100% acrylic interior paint in an eggshell or glossier sheen would be recommended.
The only thing you should use masonry paint on is of course, stone or concrete. If it's an indoor concrete floor or wall that's fine.
It's for painting concrete or brick.
Linseed oil is generally taken from flax seed. In years past it was used in paint and as a preservative for wood, iron and masonry. Its use as a part of paint is seeing a resurgence in the historic preservation of older structures.
First wash it off to remove any dust, then paint it with masonry paint . Available in Home Depot or Rona
On stone, concrete, brick and things like Hardiboard.
You probably can. As long as the masonry paint is 100% acrylic, you will have no problem at all using it on a wooden porch ceiling. Using a cheaper vinyl paint is not suggested on wood though as it will craze and crack over time.
I use TiteBond 2 for balsa wood.
Like a paint pallet that artists use to paint with and its wood!
Paint or Stucco
You can always paint faux wood shutters, but make sure to use a good primer so the paint doesn't peel.
I use semi-gloss latex.
Primer, type depends on the type of wood.
Bricks blocks or stone