Blimey, this takes me back a bit - studied Latin for 5 years up to GCSE level so I'm a bit rusty.
The dative, genative and ablative are basically different ways of saying the vowel depending on the context of the sentence.
If I remember correctly:
genitive - when you're referring to the object being owned by someone.
dative - indirect object, can't remember really, hardly ever used it
ablative - according to google: "expresses the means or tools by which one accomplishes something"
Yes, there is a conditional tense, called the subjunctive which comes in present, past, and future tense. Can't remember how you formulate it now though.