Welcome Optimist.
I am a Thal Intermedia and credit my frequent gym visits as the reason I do as well as I do. I say go hardcore and enjoy your workout. I have yet to have my Thal stop me from an activity. I take daily multi-vitamins without iron and also protein workout shakes to build muscle. Protein shakes aren't necessary, I am just trying to get bigger. I don't normally run because it burns all of my calories. Mainly weight lifting for me.
You should also be fine with studying. For me studying is when I get tired. I think it has more to do with boredom though.
Probably should workout to an extreme if you have alot of studying to do anyway. Even a non thal would be tired.
As far as being pale.
hmmm. I've never been pale. Juandiced as a kid which caused a yellowish tint to my skin, but it has long since cleared. I have noticed that the palms of my hands have more color. I think this is due to being in better shape also.
Hope this helped. Feel free to ask whatever you want and good luck on getting into post-grad medicine.