"Sepas" is the second person familiar present subjuntive form of the verb "saber". The subjunctive is used to espress uncertainty or doubt. In this case, it would probably mean "you might not know it".
Yo soy boricua pa que tulo sepas translates to mean 'I am Puerto Rican, Pa you know it.'
Look! What I...
The phrase "lo único que se puede es que me conozcas bien para que al fin sepas lo que quiero" translates to "the only thing that can be done is for you to know me well so that you finally know what I want." It conveys the importance of knowing someone well in order to understand their desires and intentions.
"To do lo que tengo es Dios" translates to "All that I have is God" in English.
Lo que pasó means "that which happened," or "what occurred." Lo que pasó es que hablábamos= What happened is (that) we were talking
Spanish sea lo que sea means "come what may".
This is what I do.
God knows what he does.
All I have is God.
"Vaya, hasta que me dijiste" would mean something along the lines of "Jeez! Now you tell me..."
It means "Did you understand what I said?"
lo que saltan