The word token in the context of Cryptocurrencies is used to refer to a digital unit of account. By tradition, this word is usually used to refer to the secondary parts of the blockchain web (Those that lack their own blockchain), while the main asset of the network that runs them are called Cryptocurrencies.
Both tokens and Cryptocurrencies are intangible assets based on Cryptography existing within a transaction register but not in the physical world, however, some tokens and Cryptocurrencies can be used as representative units of other assets (Whether tangible or not), which is why it is possible to point to some of them as assets “Backed” or “Collateralized”.
None is really better than the other, since there are Cryptocurrencies that are very good for a certain activity and there are tokens that are very good for other things, that is why it all depends on what we want to do with our Crypto assets.
No, there are tokens that can be available on multiple blockchains without any problem, since they are assimilated by these networks.
No, like Cryptocurrencies, tokens have the same level of security provided by the blockchain network and its Cryptographic security protocol, therefore both digital assets are safe.