Is an arranged employment mandatory requirement as part of exprss entry 2015

[ManjushaThota]

Hi,
I just started researching about Canada PR immigration . I have a couple of doubts.Could any of you help me clarifying my queries.

a) I was going through few links in CiC website.
according to this, as part of Step1 ,it necessitates us to register with the "Job Bank" and promote ourselves as part of Step1.
Does this imply, that I need to get an employment with any of the Canadian organization in order to receive Invitation to Apply

b) I have the following scores

Language Adaptability : 23 (IELTS Listening 8.5, Reading 8.0, Speaking 7.5 Writing 6.5)
Age : 12
Work Experience : 13 (3+years in India)
Education : 21 (BE Eng CSE, India)
Adaptability (Spouse ) :5

Total :74
What are the likely chances of mine to receive an Invitation to Apply?

c) Is there any cap in no of VISA's granted per Occupation as Part of Express Entry?

d) What is the job market scenario of Information technology and software services?

Your responses would be really helpful in planning and taking up my career decision.

Thanks in Advance,
Manjusha