I am going to write my grade & some ECs, but I am not sure if it is okay to explain(in a paragraph) how I really want to attend UCLA & the reason behind it. I want to talk about a specific academic path(major, minor, certain courses, etc.) I want to pursue in UCLA… Will it be too much??? 
I have the same question…
Yes.
@ohm888 ty! Also, i know that ucla do not rank waitlisted students, but is the waitlist depend on majors? For example, if some econ majors decide to not attend ucla, will that space go to waitlisted students w/ econ major?
Yes, it’s based on space in major.
@ekakcof Yes, I would do that…i know that some people say not to send any additional letters or details but I seen it as something that won’t hurt (what are they going to do? Take back the admit because you sent them a note?). But I would switch around what you said up there…rather than “I want to talk about a specific academic path(major, minor, certain courses, etc.) I want to pursue in UCLA” I would switch to “Here’s what I believe I can bring to UCLA and my fellow students around X specific academic path.” Make yourself someone who will improve the class overall.
@ohm888 thanks!
@SouthernHope ty for the tips! 
Does anyone know if I can make changes after I hit the submit button?
oh and just one last question, is it okay to mention some ECs that I did not include in UC application? I wanted to add more ECs but since I was only allowed to add 5 for each section I had to remove them from my application. Will they look bad if I mention them in waitlist statement, since they are not considered as new information?? 
@ekakcof I don’t know if report more EC’s as new information is ok or not at this time.
I just know that you have just 7 days to go out from the waiting list. I would try everything, and for me you have good ideas.
Good luck.