Do I have to return my all gear while transferring from Enlisted Army Reserve to active duty Army Officer?

If by gear you mean whatever the equivalent of TA50 is today, the answer will be yes. The school will re-issue it to you when you go, then you will turn that in at the end of OCS and it will be re-issue at your BOLC. So anything on your hand receipt from the unit they will want back every time you move.

After I made E7 I never drew CIF because I bought my own. Saved hours and hours when clearing post. If I could have bought a Bradley I would have done that too.

You will have to return all of your OCIE. You will have to get a new draw.