1) A 504+ would be ideal for DO's. For MD's shoot for 510+, the higher the better. With your GPA, a 514+ really should be the goal. The strong upward trend will work in your favor.
2 ) Yes
3) There is no basis to recommend schools without an MCAT score. Arguably most important part of your application is still missing.
4) Do not apply in 2 cycles. The merits of it can be debated but there is a level of stigma SDN will frequently state that re-applicants often have associated with them. Apply once when you have your best app ready.