and, I think it needs some work. You should break it off into sets (e.g. 4 sets of 20x push ups).
also, you have no pulling exercises.
also also, You should read the link that steven low asked you to read multiple times, him and Joe Brock probably know more then most of us so you should listen to them.
and lastly, This should have stayed in the other topic with people already there trying to help you out.
just sit ups for your core? there are a lot of exercises out there, here are a few that you should think about incorporating:
leg raises (various types)
russian twist (or as my old coach used to call them "rocky balboa's")
and remember, most of these exercises can be weighted, but sit-ups wont get you the results you want.