It balances after 2016 blocks, not 2 weeks. This is a crucial difference because when the hash rate drops dramatically, those 2016 blocks might take 4 or even more weeks to create.
Yes, it could. There is a hypothetical "stuck network" situation, but that really is dependent on a lot of network power disappearing. Before that you'd end up with a lot of idle hash power and ex-miners wondering what they could achieve in the way of an attack with it...