Humidity

Will humidity effect the fermentation process? I'm keeping my bucket in my 3/4 bath because its smaller and has electric heat where I can regulate the temp. Will people taking showers cause any adverse reactions?

Possibly, depending on how dramatic the shift in temperature is, and for how long. A hot steamy bathroom may raise the ambient temperature in the room into the mid-90's (think sauna/steam bath), especially if you have girls/women in the house. Mine both like to take half hour showers. Now, time is another variable as it will take time for the hot steam to raise the temperature of the beer.

What I would do is invest in a swamp cooler. It's basically a big bucket that you can put your fermenter into. You put your fermenter of wort/beer into the swamp cooler, then fill it with water (or ice, or water and ice, or water and floating ice packets) to help regulate the beer's temperature. It takes longer for the big tub of cool water to shift temperature which stabilizes your beer's temperature within it.

Freeze a few bottles of water in your freezer, and add them to the swamp cooler to keep ambient temperatures down.

Provided the beer is sealed with an airlock, it has it's own environment on the inside. Humidity on the outside will not have any affect on the beer.

As ATP said, temp fluctuations may. But steam should not heat the bulk temperature of the wort/beer very quickly, so I would say you are fine.

And yes, search swamp cooler. They work great.