i don't know all the answers to your questions, but this is what i DO know...
COMLEX 1 is given at the beginning of June or in October...expect your score in eight weeks for COMLEX...
COMLEX 2 is given at the end of August or around January
When I was on rotations this year, the interns took COMLEX 3 around December I think, but I could be wrong
Since I am applying for residency now, i cant really tell you when to expect anything. The D.O. match comes out in February, and the M.D. match comes out in March. The best thing to do for yourself is to send applications as soon as you can (unless you are waiting for your step 2 or COMLEX 2 score to come back, but by then it may be the end of October or beginning of November, which is kind of late). To ensure that you can send your stuff out as soon as possible, you need to get several recommendations during your third year so that you will have three good ones to pick when ERAS (the online application program for residencies) starts working around the beginning of September. If you make a C.V. (medical resume) before third year starts, it may help because some people ask to see it when you ask for letters of recommendation. It also couldn't hurt to start working on your personal statement at the end of third year/beginning of fourth year, because it may be nerve wracking and time consuming to write it--for me, it is the only thing that is holding me back right now from completing my ERAS stuff. The importance of the personal statement varies from program to program also, so thats another added headache. Send everything out together, because some places may not look at your application if it is not complete when they recieve it. Though I have no personal experience, I've heard that if you send out your applications right away and they are COMPLETE, you can improve your chances of getting an interview. There's a book by Iserson (Getting into Residency?) that you may want to check out. Best of luck to you.