No, if it does, there was something wrong: there were too many combustibles in your saggar or there was oil, paint or an other contaminant on or in the materials you were firing with.

Yes, my kiln is also inside. Make sure the space can be closed off from other areas and has a window so you can ventilate the room well. Do not work in the room when the kiln is on (but that also applies to a biscuit or glaze firing). 

No, it will not.
When firing a saggar in an electric kiln many people have the image of a pitfire: a lot of smoke development. However, that is not true. Because you are burning in a relatively small space (the saggar), you only need very little combustibles. You also need to make sure that everything is dry. If smoke does come out of your kiln then there were too many combustibles in your saggar or your saggar was too big or there was oil or paint on your combustibles.

Hardly, if you do it right. Your elements get a bit 'affected' with every firing (bisque, glaze) so you have to replace them every now and then. My experience is that firing a saggar does not significantly shorten the life of the elements .

You can also use the technique I describe in the book in a gas kiln, but you must ensure that sufficient oxygen continues to 'flow' through the kiln.

You can read all about saggar firing in my book:
"Saggar firing in an electric kiln."

Would you rather watch videos, then have a look at my online course.