Need Help Douts Regarding FSW Application n NOC List....

i am having douts regarding FSW Program... my exp is not in the 38 NOC List so can i apply for FSW.... i heard that sometimes application get's rejected..

i am having 3 years of exp in networking field as system administrator and i am having exp and releaving letters but i lost my job offer letter so, is the job offer ( appointment letter ) is compulsory for immigration as federal skilled worker or i can submit just exp n releaving letter. i am also having 2 years ( part time ) as trainer in networking field...

my system administrator exp does not comes under 38 NOC list but part time trainer is in noc list so, using which exp should i apply..... Thanx in advance

1) Should i apply as the partime trainer, it is in the NOC list comes under vocational trainers...

2) is my Employment letter ( Job Offer Letter ) compulsory for immigration, i don't have ...

3) Background check ( Exp Certificates ) is done through Phone or they will come to Company n do the Enquiry

4) I have a Sponsorship letter from my relative.. does my application process will be quick...