As far as the yellowing of the tips goes -

What's the ph of your water, I assume you're not using any nutrients? You want your ph to be around 6.5 - 6.8 and if you ARE using nutes, you probably are using too much of a concentration for your watering schedule.

Don't worry about the stress, the plant is still young and it deals fairly well with stress such as you've described. Your cat could've potentially killed it though, you got lucky there.

The first two leaves browning and dying is normal, don't sweat it, it's just shedding old inefficient leaves

And you want to try and get your plant in an enclosed area with mylar or, white paper, or white paint in order to reflect the leftover light from your CFL to the bottom of the plant. Plants always reach closer and closer to their light source. Moving the plant / lights away from each other is something you'll always have to do

Word of advice my friend, next time you have a simple question that sounds like a newb would have asked it before, use the search bar on these forums or use google to search for your answers. You gotta do your own research man, that's what we all do.

SEE THE FUN IN READING!!! :thumbsup: