My understanding is that a liana is simply a tropical vine, according to various online dictionaries. "Liana" and "vine" are almost synomyms; they are both creeping/climbing plants. The only difference between these two words is that a liana characteristically grows in tropical places whereas a vine grows in any other type of environment. Thus,to put it another way, you could say that a liana is a type of vine, but a vine can be a liana only if it grows in a tropical environment.
To answer the second question, plants that are creeping (developing gradually over a period of time) or climbing (growing in an upward direction) are both representative of vines. If the creeping/climbing plant grows in a tropical setting, you can say it is a liana.
In short, it all depends on which environment the vine grows (tropical or non-tropical).