I don't know about Maldives, but for Sri Lanka, all you need to enter are a passport, onward ticket and (theoretically) proof of sufficient funds. Having the onward ticket for the next leg of your itinerary should answer any questions they have about your visit and plans should those arise.

It certainly looks like Sri Lanka issues a full-page visa on arrival for tourists but it's not entirely clear and a full blank passport page is not mentioned as an entry requirement anywhere.

It would be worth checking with the embassy in Switzerland, though, as the U.S. State Department is reporting that Sri Lanka has plans fairly soon to introduce an online visa approval form for tourists but has not announced an exact date when the new system will be up and running. That suggests you should double-check two weeks before your departure to make sure there haven't been any sudden rule changes.