Hi Venkat,
I am not sure what are the possibilities for a SAP PO/PI consultant in the market.. It would not be correct to give a recommendation without a real perspective.
I just can mentioned a few things related to APO SCM.
Let me try to share my opinion of your 4 points:
1- I think most of the companies that have ECC will choose APO SCM rather than a SCM application in other platform (like oracle). So the comparison against Oracle would be correct if you are evaluating to convert yourself into a consultant of an Oracle Solution and this is not the case..
If you compare SAP vs Oracle, Oracle seems to be in the first place, base on forbes:
IDC's Business Analytics Market Share Update Shows Oracle In The Lead - Forbes
2- I am not sure if we can tell you how much time you will take to settle down. This depends on you and on what settle down means for you. It also depends on if you have a Supply chain background or not. If you don't you maybe will be working in the dark.. meaning that you will be learning lot of things without a real idea of what you are learining.
3-If you have or not ABAP knowledge is not relevant. You can be a very good SCM consultant without any knowledge of ABAP.
4- I don't understand what do you mean with this expresion (sorry about it). Just note that you carreer depend 100% of you.
As an additional comment, just note that SAP is being ending the support of APO in 2020. This does not means that APO will disappear.. just wanted to let you know that something new is coming.. read about HANA, APO, etc..
Here you have a thread to start with a reading:
Will SAP substitute APO with some other tool ?
Good luck!
Kind Regards,
Mariano