1. Normally no. Unless you cracked Okuma CPU or you have installation distributive of exact the same model OSP.
2. What's the question? What kind of instructions machine is asking for? Press the big green button and it will run.
3. connect to RS223 interface ( DB-25 ) at OSP side normally. Recommendation: use hard hand-shake ( CTS, CTR ). Cable is more complex but the communication easier to trouobleshoot in case. And so on ... One more point. Check the OSP Data Management Card: maybe you are lucky and the machine has DNC function. Means: you can "feed" the part program through RS232. here is a little help on that.
4. What is the question? You want to learn scribe and run the part program?