well, Grey Wolf Star, i have to say that ur pinyin passage really gimme the works and baffles me alot. better to use some simple chinese wods to express what u wanna say. so that's my "decoded" guesswork and hope it'll b helped.

ni hǎo, wǒ shì Hannah = Hello, i'm Hannah.
better to say "wǒ jiào Hannah"(我叫Hannah) natively. jiào means "named..."

wǒ shì 16 suì. = i'm 16.
it's alright to say "i AM 16" but in chinese, the predicate shì(am) is always dropped out.

wǒ shì yí hàn wèi wǒ bú kè yòng tú Zhōng guó xiě zuò = i'm so sorry but i can't use chinese to write
is that right? if so, the right pinyins r "wǒ shì(hěn) yí hàn wèi wǒ bú kè(néng) yòng tú zhōng guó(wén) xiě zuò" and into chinese "我很遗憾我不能用中文写作"

dàn shì wǒ shì yòng tú yī gè xiàn shàng cí diǎn = but i could use online dictionaries (to help me)
bingo? the corrected pinyins r "dàn shì wǒ shì(néng) yòng tú yī gè xiàn shàng cí diǎn", into chinese "但是我能用线上词典"

Wǒ bào yǒu qià qià kāi dòng xué wèn Zhōng guó bìng wù bào yǒu cún qǔ zhì mǒu wù bǐ róng xǔ wǒ rèn wǒ shì yòng tú duì le cuò cí
my! sweetie, r u speaking klingon? ))) gimme more details or write them by simple words, okay?

and btw, my personal suggestion, i mean, u'd better add ur english means as the so that more people could give u detailed corrections. anyway, easy does it and good luck, mademoiselle )))

迪斯尼动画片《花木兰》

今天我又看了看动画片叫 «木兰»。这是我最喜欢的儿童动画片。动画片（是）关于作为一个男人打扮（成男人）的女孩叫木兰。她是中国古代民族女英雄。她来替父从军，击败北方入侵的民族。很漂亮（精彩）的动画片。我还看过了英语翻译的花木兰民谣。<a href="http://www.yellowbridge.com/onlinelit/mulan.php">http://www.yellowbridge.com/onlinelit/mulan.php</a> 我很喜欢这个民谣， 因为它揭示（?）妇女的智慧和力量。

about the word underlined: "揭示" isn't so proper used in here, mine personally. "揭示" means "disclosure, reveal", which contains such a signification that to make smth hidden known to us, like top secrets, unknown laws, nature phenomena and proved theorems etc. but here obviously, u have the commendatory tendency for female's power and wisdom, so y not use "展示"(show), "赞美"(praise) much better or "讴歌"(eulogize) formally rhetoric. and the bonus info for u, julia. Mulan is not the only heroine character so well-known in the ancient chinese literature, another famous woman is Mu Guiying (穆桂英), as the spearhead general under the command her grandma rallied the troop and bloodily fought with the enemies. this story named "the Woman General of Yangs"(杨门女将) and later transcribed to a beijing opera called "Mu Guiying Takes Command"(穆桂英挂帅). hope it'll b helpful ))

我的中文水平不怎么好，还望大家见谅

虽然（因为）从小接受中国文化的熏陶，（所以）我很喜欢中国的文化传统。但是我的同学说我的中文说的怪怪的，我不知道为什么他们会这么说我。中国同学都不喜欢日本同学，（但是我）真想在网络上交个朋友

孔明灯为什么又叫天灯？

<em>天灯为什么又叫孔明灯？—— it‘ll b better, "天灯" aka "孔明灯"</em>

星期六我计划去看看放天灯的表演。希望这是（一场）很美丽的表演。我打听（过）了，（之所以）天灯叫做孔明灯，因为古时候有个人叫孔明，是他发明了这种灯，（另外）放孔明灯的时候人们还会许愿。

<em>and about the slight slip which is underlined: he who invented the Kongming Lantern(天灯) is Zhuge Liang(诸葛亮), whose style name was Kongming(孔明). and chinese people seldom call an ancient his style name directly and instead, with his surname preceded or his full name. so it'll b much better to say "因为古时候有个人叫诸葛孔明 / 诸葛亮". but it'll b somewhat impressive to chinese if a chinese-learner could bring out style names coz that shows u may know chinese culture or history well )) anyway, enjoy the lantern show and feast ur eyes, dont forget to make a wish )))</em>