The issue that you have posted is more than a single question and in fact is a project. Projects are pretty much out of scope for the intentions of the SQL forums. My suggestion is that you get a consultant to help you -- especially if the timeline
for completing your project is near critical.
The next best option is to get a book and do some research to the steps that are required.
Yes, there are many problems that come into play when converting from Oracle to SQL Server. Here are a few:
Oracle has PL SQL; SQL Server has Transact SQL
Oracle has the MODEL verbiage; SQL Server does not
Oracle optimizes queries differently than SQL Server
Oracle scalar functions tend to be a bit more efficient than SQL Server scalar functions
Oracle returns results result sets from procedures very differntly than SQL Server does
Oracle has no equivalent to SQL Server inline table functions
Oracle table functions do not translate well to SQL Server (
Oracle XML operations are vastly different than in SQL Server
Oracle recursive CTEs work very differently than the way CTEs work in SQL Server
SQL server has no direct equivalent to Oracle sequences, although this should get better with the next release of SQL Server
(That is 10; that is all I am going to do; please do some [make that A WHOLE BUNCH!] of research into this. )
Stand by and I bet you get some good suggestions to follow.