Yes or it can be the same as the wall paint if it should be flat.
There are different kinds of satin paint - you'd have to know if it was latex, oil, enamel, alkyd etc.
You can use either water or oil based paint, which are both available in a variety of sheens to paint molding. Water based satin coatings are very popular for crown molding in 2012 and have been for several years, while an oil based semi-gloss are the best choice for baseboards and door moldings where available.
Sure you can!it will work just fine
Many hotels that use paint use satin or semi-gloss latex paint in their interior applications.
If they are both of the same base you can. Satin paint can be an acrylic or a latex,or an oil. Check on the can cleaning instructions for base. Jason Pollock used both in his work 'Bluepoles' which hangs in the Canberra museum I think
Yes as long as you use the same base paint. You just need to sand it enough to where the paint will adhere. Make sure if the original paint is latex, use latex. If its oil based, use oil based.
I don't believe you can put latex paint over an oil base. it will never dry and will always be tacky
Generally, a satin or semi-gloss sheen is best for decorative trim. The shinier paint will be a bit easier to apply, be smoother after application and will accent the crown molding. I always paint crown, doors, door trim, and baseboards in high gloss. Here in the south we also use only one color, white. I also use ceiling paint as the primer coat because I paint it (the crown moulding) when I paint the ceiling. Then I apply 1 coat of high gloss on the crown. Then I paint the last coat that has been thinned a little with water (2 tablespoons per cup of paint) This goes on very fast and smoothe and when finished looks like wet vanilla ice cream. When you paint high gloss, be advised that you have to keep a wet leading edge, meaning that if you stop painting and the paint is allowed to dry, it will show where you stopped and then restarted. The same is true for semi gloss and satin.
LOL...no sorry, it will just be a bit shinier than anticipated. (gloss is quite scary if painted over an entire wall - better for trim and cabinets, etc)
No. They have different textures and looks.
More important is, that both paints are of the same kind (like: oil-based paint, acrylic paint, latex paint). Semi-gloss is more easily painted over then high gloss, but first better find out what the old paint layer is made of. Check with the help of alcohol - if paint comes off in any way when you rub it with a cloth of alcohol, it's latex or acrylic paint (and can be painted over with acrylics).
Use a Exterior Latex Satin paint......You can spray on or use a zip roller low nap! You will need a brush to cut in where roller cant get.