As long as it is solid and has no high or low spots greater than 3/16". ABSOLUTELY!
yes depending on a few factors, such as levelness of exisitng floor, height, and condition.
Depending on direction of flooring being lay-ed, I like to weave my floors into existing floor to make the repair or add on look like it was originally lay-ed with other floor.
Yes you can, if you are talking about a floating floor, like pergo.
yes but only up to 3 layers
If you are you are referring to tongue and groove flooring such as Pergo then the answer is yes. You may however want to first lay lu-on (not sure of spelling but it is a thin sheet of wood) to insure that the floor is level.
Laminate doesn't have to lay counter to the floor joists like traditional tongue and groove wood flooring. Manufactures state to lay the floor so the grain will be running opposite of the major light of the room. Also in narrow rooms you might want to consider that the grain should run the length of the room to help make it look larger.
A hardwood floor can wear down over time, creating lighter colored spots on a floor. A floor refinishing gives new life to hardwood flooring, giving it the same appearance as new flooring. When refinishing a floor, it's important to sand off any existing finish. This can only be done on true hardwood floors - vinyl flooring with a wood veneer will be permanently damaged by sanding. After sanding, lay down a layer of stain on the flooring. Add a layer of polyethylene to protect the wood. Allow the flooring to dry for at least 24 hours, then buff the floor complete the refinishing job.
Yes, as long as the floor is smooth and level. Don't forget the pad for laminate if it isn't already attached.
You can but I would lay plastic down and make sure that there is a 3/8 inch gap all the way around for expansion due to humidity changes, you can cover the gap with baseboard.
It makes a better finished product to remove the old flooring first.
I have never seen a metal floor cover in any mobile ( and have seen hundreds) If i was modifying this I would lay K3 or plywood as a subfloor and cover with carpet or engineered laminate flooring.
A smart choice would be to get teak flooring installed. It is a tropical hardwood found in the jungles of South America so it can withstand heat. It is very sturdy and does not need any varnish at all.