Perhaps, but not guaranteed. Tile is generally much heavier than asphalt or "composition" shingles. If you're concerned, have a roofing contractor to evaluate your roof.
With composition shingles, no felt is necessary between shingle layers. When the exposure of the shingles is the same as the old exposure, the bottom edge of the old shingles is used as a guide for the upper edge of the new shingles in placement. This ability to place the shingles would be lost if covered with felt.
In general, this is the recommended replacement schedule based mostly on the material used: Composition Shingles: 12-20 years. Asphalt Shingles: 15-30 years. Wood Shingles: 20-25 years.
no
If there is only one set of shingles on the roof, cover over it. If two, remove the old and then apply the new.
no, because eventually it will dry out and crack, or blow off. the shingles are built to withstand the heat, rain and wind.
You can, but it is not recommended. It used to be done all the time when asphalt shingles first started to be used. It makes for a lumpy roof and will puncture easier from hail or being walked on.
They are probably not metallic, but are grit that has washed off the roofing shingles.
That is related to "composition", the composition of functions. That means you apply one function after another. f(g(x)) means you first apply function "g" to the variable "x", then you apply function "f" to the result.
Can I apply lawn fertilizer after rain/
80 squares is a measure of area, it doesn't apply to length.
It depends on the state approved rate structure and underwriting guidelines of your insurance company. You would need to call them and ask for a quote based on composition shingles rather than wood shake. Some companies do not accept homes with Wood Shake shingles at all. It's not likely to effect your rate very much with a single insurer, however, having a composition shingled roof would open you up to a much wider range of potential insurers that would accept you thereby allowing you more of a market to select from.