First, about myself:  I do not have BPD. By this I mean I have never been diagnosed, nor do I believe I have BPD. 

A good friend of mine was diagnosed with BPD a few years ago. We live on different continents and so don't get to speak all that often. In our last few conversations she spoke about what it was like to have BPD. She spoke about her thought processes, how she tended to perceive things, and her experience with many of the symptoms. 

From these discussions, I noticed two themes which I found puzzling. I wasn't sure how to go about asking further questions, so instead I decided to look around online to see if I could find any insight. I have since seen these themes in the writings of many people diagnosed with BPD both here and on other sites. I figured I would ask for insight about them here.

- Confusion over whether one likes somone (in a romantic sense), or whether one merely likes the feelings that person evokes in them. I am not sure I understand entirely this distinction. The people I have liked or loved romantically have always made me feel a certain way. Their actions towards me made me feel things, and the act of thinking about them or interacting with them made me feel things. These feelings were a large part of my like/love for them, and I don't entirely regard them as separate. So I suppose I am confused about the nature of this confusion. 
 
- The notion of depending-too-much. I certainly think it is possible to be overly dependent on someone or something. However, with my friend and others it would seem, there is some disparity between our ideas of how much is too much. Of course, this will be different for everybody, but the disparity seems rather large here. For instance, my friend has told me in the past she felt she depended on me too much because she called me at times when she was feeling stressed. I wasn't sure how to respond, because I feel this is just part of friendship. I didn't really perceive her behaviour as dependent. The thought never crossed my mind. I guess here my question to you is: how much is too much, and why do you draw the line where you do?

I would like to clarify that my interest is simply rooted in the fact that I genuinely don't understand what I have noticed, and I genuinely want to understand. This is only for the sake of understanding itself. I know that, as someone who does not have BPD, understanding might not be entirely possible.