Nonetheless, there a some reasons that just keep me away from doing it.
1. The reactions of others. I think everyone has or had some problems with this one, but I fear how my family and friends will look at me since I know they wouldn't like the look; especially since everyone only knows me with "longish" hair.
2. My head is kind of... weirdly shaped. I don't know how to explain it, but I already noticed it a couple of years ago, although I seem to be the only one bothering with this. However, the shape would become a lot more visible when sly so perhaps I look ridiciolous with a shaved head.
3. People keep telling me my facial (and partially, body) features were kind of feminine and soft, and yeah I kinda agree that's why I kept my hair long... and having a "girlish" face with a shaved head would probably look strange =(
Ok, Kai I've looked at your pics and I have to say "you have nothing to worry about". You don't look "feminine" and you look fine with all that hair although it is pretty long at the front which is also fine if that is how you like it. It is completely normal for the hairline to start receding a bit at 19 also -- so that's also good.
The 3 reasons that stop you:
1. Reactions of others:
Personally I had no bad reactions at all and found the whole transition as easy as pie. The key is not to care about what others think
and to not care about what you think. There is a part of the mind that cares about stuff and worries and a part of the mind that just witnesses or is aware of what is going on. The aware part can't act or do anything -- it can only be aware. Bring this to the foreground of consciousness and the worries sink into the background -- they may still be there but their impact will be greatly lessened.
Also bear in mind that any reactions of others will be very transient -- it will only take a short time for them to go back to worrying about how
they look. Expect some people to silently admire you though for having the courage to do what they want to do but can't because of similar fears to what you have so well articulated.
2. Odd shaped head:
Many, many people worry about this but it is never a problem for anyone once the deed is done. Personally, I didn't even think about it before I did it but after I had shaved I noticed that my head-shape was fine and dandy -- what a nice surprise. I am prepared to give you a money back guarantee that this will not be a problem for you. The photos show no potential problem also.
3. Feminine tending face with bald head looking odd:
I don't think that you have a feminine looking face at all. It look masculine but
young -- which is good because it is young. If you feel that you have a "feminine" or soft body then that is easily fixed with a bit of exercise which over a few years will make an enormous difference if that is what you want - but I wouldn't worry about it. Also remember that bald women [who obviously look feminine] do not look strange at all -- look at Dee Dee Bridgewater [
http://www2.slybaldguys.com/smf/index.php?topic=19221.0 ] and tell me she is not beautiful.
Download and watch the whole series of "Breaking Bad" if you haven't seen it and look at it again if you have. So many of the actors there had shaved heads that it was ridiculous -- that's what did it for me. Pretty stupid reason but there you have it. I reckon that with a shaved head you would look like the protagonist "Jesse" when he shaved his head. I can't find a pic right now of him with a shaved head but this is him with really short hair -- use your imagination.

A bald head would give you an "edgier" look.
You will feel a great feeling of freedom in being liberated from your hair worries [free of the "tyranny of hair"] but remember -- it is easily and relatively quickly reversible for someone such as yourself if you change your mind. I reckon that everyone should do it once in their lifetime just to see what it's like. Look at Crusher -- he's even younger than you and in still in high school and he reckons that he's never going back.
Of course, you could also go the shorter and shorter buzz-cut route to make the adjustment and that might work for you -- so many different paths to happiness to choose from.
Best of luck.