As for (2), you don't quote either the size of the slot in your dropouts or the diameter of the axle in your wheel, so it's difficult to answer your question exactly. What can be said, however, is that it is not unknown to file a 'flat' in the thread on opposite sides of the axle to allow it to fit in the dropout. You could, instead, open up the slot in the dropout with a file but the former is more useful if you don't want to modify your frame. If you do decide to file the frame dropouts, remember to file the lower face, not the upper one. This will ensure the left and right dropouts remain at the same height in relation to each other and the wheel will be straight in the frame.
This might help with (1):
http://sheldonbrown.com/frame-spacing.html
Also this:
http://bicycles.stackexchange.com/questions/8725/100-mm-front-hub-94-mm-fork-dropouts-options
As for (2), you don't quote either the size of the slot in your dropouts or the diameter of the axle in your wheel, so it's difficult to answer your question exactly. What can be said, however, is that it is not unknown to file a 'flat' in the thread on opposite sides of the axle to allow it to fit in the dropout. You could, instead, open up the slot in the dropout with a file but the former is more useful if you don't want to modify your frame. If you do decide to file the frame dropouts, remember to file the lower face, not the upper one. This will ensure the left and right dropouts remain at the same height in relation to each other and the wheel will be straight in the frame.