Dude, go back and look at all your threads. You're asking us what we think of seemingly every female interaction you have, and asking if it potentially means she likes you. This can only leave us to assume you are EXTREMELEY DESPERATE and probably act that way in person, hence why girls are "seeming interested and then suddenly not", most likely because they can sense your insecurity and desperation. You will honestly have a better chance of getting a girl's number by slapping her on the ass and calling her your bitch than you would by acting nervous, sex starved, unsure, inexperienced, etc.. TRUST ME girls pick up on that kind of body language 100x better than us men can.
Just get out there, talk to as many women as you can, pretty, ugly, fat, skinny, black, white, talk to them ALL and talk to them often, and you will be answering your own questions before no time, not to mention probably getting laid at that point too. Don't be so scared of women, they're human beings just like us. They eat, sleep, burp, fart, piss, shit, pay bills, go to work, get sick, get stressed, get tired, get happy, get sad, want to have fun, want companionship, want friends, want sex, etc, etc, etc...just like you do. Now go talk to them as if they were just another guy, watch the results. Don't pitch-up your voice when talking to a girl (common youngster's mistake), don't change your persona, or lingo, or usual behavior. Chances are she's talking to you right now because she observed you acting normal earlier. Now if you change and start acting all soft and different, you bet they're going to "suddenly walk away". Don't expect a woman to ever let you know what you did wrong as they're walking away either.....unless it was something pretty damn obnoxious that you did.