I would suspect the chief pilot position would need a commercial pilot ticket (and a 2C medical)? As Firstimeflyer mentioned, you need to find out what the minimum required qualifications are, and also what the competitive qualifications are. Sounds like you'll have time to do what you need to. I ask because you generally need a CPL to get paid to fly, and I trained some LE types who were trying to break into their flight department and they all needed a CPL.

Taking time off to get each rating done in a block will probably be more cost-effective. Folks who train part time often end up taking two steps forward/one-step back if they train less than several times/week.

Regarding the IR...flight experience in actual IMC is invaluable...if you're going to try to knock that one out all once as well, try to pick a time/location such that there will be ice-free clouds to fly around in.

The FAA written tests are not exactly aligned with what you will be asked on your checkride. For that reason I recommend getting the written done early in the process so you can set aside the multiple-choice mentality and focus on real knowledge for flying/checkride. Do not take the written the day before the checkride...