Can you explain the parts [(number) ... ]?

Howard: Oh really, did you make a second date?
Leonard: Well, we sort of decided to wing it.
Sheldon: Oh, even I know that's lame.
Leonard: Okay, alright, [(1) let's assume your hypothesis]. We went to dinner, we talked, we laughed, we kissed, where could I have possibly gone wrong.
Howard: Think back, Leonard, the littlest things can set women off. Like, "Hey, the waitress is hot！ I bet we could get her to come home with us." or, "How much does your mom weigh? [(2) I want to know what I'm getting into]."
Leonard: I didn't say anything like that.
Howard: Good, ‘cos they don't work.
Raj: They also don't care for it if you stare at them and hyperventilate. Sadly, [(3) that's my home run swing.]
Leonard: Look, everything went fine. I didn't even have to [(4) refer to my impromptu conversation starters]. The woman across the hall is into me.
Howard: Let's go to the tape. Look at her reaction to the goodnight kiss, no change in respiration, pupils un-dilated, no [(5) flushing of the chest.]