Tom has never been to Madrid, but he talks as if he were there himself.
Tom is talking as though he is currently in Madrid.
Tom has never been to Madrid, but he talks as if he had been there himself.
Tom is talking as though he went to Madrid previously, but you know he is not in Madrid right now.
-tive / -ative is a suffix that turns certain verbs (usually ones ending in -ate but it works with talk, combat, act, prevent and probably a few more others) into an adjective. (Note that there's some words ending in tive / -ative that are adjectives but don't map to a real English verb, like tentative or native.)
In the case of X is appreciative of Y the meaning is "X is doing things that show appreciation of Y." It does mean the same as "X appreciates Y," it's just a fancier way of saying it.