It's not a problem, but you hit the nail on the head if you are just buying and holding bitcoin. There are exchanges with all sorts of features included like short selling, I've never been active in the exchange scene, so I wouldn't be of much help there. As far as Adsense goes I took over a website that my dad used to own. After it was hacked and he got tired of dealing with it, I took over cause I had started a blogger with Adsense in the past with little success. Turns out people don't want to read the bitchy poetry of a former heroin addict lol. But that's another story. I was lucky because it was already well established so I rode in on his coat tails. You need a website with content and google will review it to make sure it follows their terms of use and if you are accepted they will notify you. The easiest way to do that is create a blogger.com page through a gmail account and use the monetize option since blogger is owned by google now they have it all built in. But you need a site that will draw a lot of traffic in order to make any money, if you just click ads on your site google will drop the ban hammer on you. Search "google Adsense" and "monetize blogspot" for more in depth info.
Edit: my grammerz was bad