Sorry, I don't know how to say "female students" specifically. But, I think whoever you say this to will assume you mean female students. 화장품 (메이컵)을 하는 학생을 많이 봐요. I don't know how to romanize hangul. Here is my best try... Hwajangpum uhl hanun hakseng uhl manhi bwayo.

I'm assuming this was a comment on social media and also the person is using some colloquialisms, but I'm pretty confident that this is what they said. As soon as I saw your picture, I felt like (or "thought that") I wanted to follow you! Let's follow each other. If you write it more formally it's like this 저는 네 사진을 보고 맞팔 하고싶단 생각이 확 드네요! 우리 맞팔해요. Breakdown: 저 (I) 는 (subject particle) *This part is omitted a lot in Korean. You just imagine it was there. 사진 (picture) 을 (object particle) 보 (see. from 보다) 고 ("and") * This person said 보구 which is like spoken Korean 맞팔하(다) (follow, specifically on social media) 고싶단 ~ 고싶다 means "want to ~" 생각 (think. but combined with the last word it becomes past) 이 (particle. sorry I can't explain this one) 확 (this is not really a word as much as it is a sound. I don't think it formally has a definition, it just emphasizes the idea of "totally" or "instantly") 드네요 (feel) 우리 (we,us) 맞팔해요 (let's follow) So 해요 has a lot of meanings. It could be present tense, future tense, or "let's" In this case because he/she said 우리, I think he/she means "let's" Hope that helps you!

You have some choices. I wrote 2 different corrections:

1. Typhoon

The weather is very hot in summer. But, a typhoon is coming. So, maybe the weather will become cool. 

2.  Typhoon

In summer, the weather is very hot. But, maybe a typhoon will come and the weather will become cool.

It is hard to explain. Maybe this video can help you http://www.ehow.com/video_4940635_what-singing-runs.html Basically, while singing the same syllable you jump or "run" from note to note. Mariah Carey and Whitney Houston are pretty famous for incredible runs.