Is it possible to resolve a contract address with ENS? The reason for the question: if so, then could someone just change resolving address pointing it to some other address?
ENS implements resolver contracts, which can point to a final terminal address that can be changed if the contract is written that way. According to EIP137, the example standalone resolver contract shows an example of how you could change what the ENS domain points to. This is really the point of ENS, as described in the abstract:
This permits users and developers to refer to human-readable and easy to remember names, and permits those names to be updated as necessary when the underlying resource (contract, content-addressed data, etc) changes.
So, you're exactly right. If you wanted to deceive people (for example, in an ICO), you could create an ENS domain and then change the address that it resolves to maliciously, thus redirecting funds for your own gain.
However, most of the time this isn't the case. Since it's implied that the owner of an ENS domain controls it, the usual implication is that sending funds to said domain will get to the domain owner anyway.