1. Indubitably. Adverb - In a manner or to a degree that could not be doubted. Sounds funny when those crows from The Simpsons say it.
2. Sometimes I'll just press alt + z for my pc dic. and look for a better word when I'm typing.
3. Seeing and hearing are very important, touch is handy, taste is yummy so that leaves smell. Since my nose is normally blocked due to having a cold I could live without smell much more easily than the other four senses.