Probably not but call your local gunsmith
NO
No, the Remington Model 1100 stock has a hole (recepticle) through the inside of the stock in the pistol grip area to accept the action spring tube. The Remington Model 870 stock has no need for this hole so the 870 stock will not fit on the Model 1100 action.
No, a Remington 1100 stock will not fit on a Sportsman 58. The two shotguns have different designs and stock attachment mechanisms, which means they are not interchangeable. The Sportsman 58 is an older model with a different mounting system compared to the Remington 1100. Therefore, if you need a replacement stock for a Sportsman 58, you will need to find one specifically designed for that model.
no
No
Remington 760 magazines made to hold the 35 Rem or any other of the short action cartridges...i.e 308, 243, 6mm.
Yes they are interchangable.
no
no
yes it will all you have to do is to take it apart
no there are some minor adjustments to the safety area
No