From what I understand, Intel is very competitive and it would help you to do much (much, much) better on the ASTB. SWO may be a more realistic goal as far as these scores go. For SWO you would need to greatly increase your scores also. Good luck man; just keep studying until most of it is second nature to you, even if it seems that you know it at the time -keep studying. I think 3 weeks is enough time to greatly increase your scores, and if not you can always study longer.
The math section is about practice, and with a lot of practice the numbers become familiar to you and you can manipulate them quickly.
Sounds like Verbal is your stronger section and it is hard to improve that any way, so I would focus on the rest.
The mechanical section is also about practice, but more importantly understanding and conceptualizing each problem (and look out for a few possible tricks on the exam, although the answer choices caught those easily for me).
The SAT section is about being comfortable with the drawings. Know the 3 steps: Bank (direction, and steep{=45 degrees} or baby bank), Pitch (either up or down, or level...easy), and Direction. The direction part is probably the hardest, there are along coast, to sea, to sea diagonally, to shore, and to shore diagonally.
The aviation and nautical parts are about studying as much as you can, and then more. First of all know the basic aviation things, i.e. pitch, roll, yaw. Know those in depth, everything about them. Know about what causes lift (physics wise) too. That is the absolute basic stuff. There is a Marine gouge study list on this section. Try and know all this stuff.
This is a very understated gouge, but it should help at least get you to 50, 5, 5, 5. Like I said, just keep studying. If you have school or a job put aside 2-4 hours a day to study. Even studying 1 hour a day should increase your scores. And if you do well, shoot for the Intel spot. Good luck and PM me with questions if you have them (i.e. mechanical concepts).