You will be able to travel space available (free in economy and with a small fee in the Polaris cabin) as well as in the jumpseat (if the flight is full). We also have a discount for purchased tickets as well.
As for the scheduling question, the best you will be able to do with the preferential bidding system we use is two big work blocks requiring two commutes (only 1 in a vacation month) a month. You can waive certain restrictions as a lineholder and compress your trips into two workable blocks of flying. It was stated earlier that the Guam base has the ability to compress even more than the lower 48 domiciles which is true. Guam based pilots can work a single work block a month with several weeks off in between. Might be worth considering. EWR 737 FO on reserve to start will be tough but doable with two work blocks of reserve days. Best of luck!