DHH is actually born in Copenhagen, Denmark, so I don't think he would need a vacation home in Italy just so he could drive his new car. But they do have bigger restrictions on the roads in Denmark...
At the beginning you should have focused app, that does one thing very well, 10 times better than anyone else. Then (if that sticks) you should gradually add features, but only if that makes user experience that much better. I've seen a lot of great apps do that and win big time. I think Twitter has a lot of problems with fail whale, so maybe they don't have the time (resources?) to expand their core product.
I'm from Slovenia, but I think most European faculties (colleges in Europe) don't charge students for degrees. We pay that through taxes. I hope that answers your question.
I'm from Europe, and my electrical engineering degree didn't cost me a single euro. So with me, it was more question like "Is it worth the time? I could spend time on something much more interesting."