Everything looks good, mate. You got the right type of bulb, but I would put one over your other cup too.

I can't really tell you how much to water, as I don't know much about it. But I know that one of the most common mistakes that new growers make is overwatering. So just make sure your soil is all muddy and you should be OK. Unfortunately I don't know anything about the purple leaves, either. Sorry!

One last suggestion I can make is to get a cheap little desk fan. Having a gentle breeze on your plants will make it stronger and more able to stand up under the weight of the heavy buds!