1. Yes - pee is high in nitrogen, so add a little urine during flowering (not sure how much, it was 1oz of pee to 10 litres I think).
2. No. The only way to maintain the high level of THC in your plant is with love and care. Otherwise, the THC level will hugely diminish. Also, if you smoke it wet then the acids etc havent turned into their psychoactive form - so make sure its dry to get high!
3. Sorta. You can add different smells to it by adding some banana peel/orange peel/apple peel etc when youre curing it, but make sure the peel isnt touching the Herb otherwise it will go mouldy. Sometimes you can taste the apple/banana/orange through the Herb aswell. Try using flavoured tobacco - my personal favourite is vanilla, as it doesnt taste like baccy at all or leave that horrible rollie smell everywhere, just a slight hint of vanilla.