1. yup, you're right! the 2 weeks vacation is included in the overall 24 mos
2. you need to phone CRA and request for your option C print out and that will only take 10 working days for you to receive it (pls. note that you request all of your option C printout and include all of them in your application just to be sure)
3. yes, you need to get a police clearance both from the city where you are actually residing right now and of course, to your home country (in my case i got my clearance also known as NBI clearance from my home country, Philippines)
4. just go ahead with your application, don't wait for your next tax returns cause it will just cause you some delays (just send what you only have right now)
Tip/s:
While waiting for the time that you can already send your papers, what you can do for now is gather all the possible requirements that you can. Fill-up all the applications so that when the right time comes, you're good to go. It's really stressful but in the end, it will be worth it.
Hope these infos of mine will help you on your application. Just keep posted