1) what position are suitable to me most and what other skills that i'm lacking off?
-System enginer or network administrator for some company.

2) what about my salary.. i know my qualification is quite low but with great responsibility i think i deserve better.
-Lower abit... can get slightly higher

3) what prof. cert. that i should get to enhance my qualification?
- Can enhance by taking degree/Master (part time ?)

4) how much salary i can get at other places?
- 2500-2600 shouldnt be problem

Good luck