Translation:She would like for you to think about that.
My problem with subjunctive imperfect is that the English translations do not have consistent tenses--sometimes past, sometimes present. Is this a mistake in the translations, or do we just have to get used to the irregularity? Which tense would be considered 'standard' (ie more common) for English translation?
The imperfect subjunctive can translate to the past or the present depending on context since it deals with something that is "irrealis" - we don't know whether anything is even going to take place.
Sentence #2 is an incorrect version of Sentence #1. "Like" is a transitive verb and requires a direct object.
From Swan's "Practical English Usage":
""It" is used as an object for an "if-clause" with the transitive verb "appreciate." (similar to "like" as both are transitive verbs)
Reversing the clauses in Sentence #1, you can see the need for the object "it":
If you thought about that, she would like it.
The verb in the main clause usually determines the tense of the subjunctive verb in the subordinate clause in Portuguese.
In this case, "gostaria" is similar to "would like". It is used to make a request less direct and, therefore, more polite. Portuguese makes this obvious with the subjunctive verb while English doesn't usually do that.