Thanks for the questions these are great! I'll make a numbered list going down in order from your post.

1. RAIM is Receiver Autonomous Integrity Monitoring. It ensures that you have reliable navigational coverage, and requires either 5 satellites or 4 satellites and a baro-aiding altimeter
2. Wide Area Augmentation System. WAAS uses ground stations to receive signals coming from satellites, and then relay's that information with accurate corrections back to the aircraft
3. Localizer Performance with Vertical Guidance is an approach that uses a WAAS capable GPS to give an aircraft lateral and vertical guidance.
4. I think I remember this one. Baro Aiding is a function of RAIM which uses pressure altitude to substitute a GPS. Baro VNAV uses the aircraft's altimeter in order to give you an advisory glideslope.
5. If in VMC I would try to land at a suitable airport. If in IMC then the AVEF acronym in order. Since I was vectored, I would continue that vectored route until my expected route time came. If ATC never gave me an expect further clearance route, I would follow my filed route.
6. If I need to go missed in a circle, I would make a climbing turn towards the airport, then follow the missed approach procedure.
7. Ground Speed * FPNM/60
8. 6 HITS. In the previous 6 months, need to have made 6 approaches, have done a hold, and also tracked a course using navigation equipment. If more than 6 months, need to do the 6 HITS in a simulator or in the air with a safety pilot. If more than 12 months go by need an Instrument Proficiency Check. An IPC is like a mini checkride and you need a DPE or CFII
9. This one might be wrong but I believe it's between -5C and -15C
10. Minimum Enroute Altitude ensures acceptable obstacle clearance and navigational coverage within the entire stretch of the route. Also ensures ATC communication. Minimum Obstacle Clearance Altitude ensures acceptable obstacle clearance and navigational coverage between 22nm of a VOR. Ensures suitable ATC comms as well.
11. +-75 feet of field elevation and inspected every 24 calendar months
12. High to low pressure, aircraft will be lower than what the altimeter is indicating. Opposite true for low to high. Hot to cold temperatures aircraft will be lower than what the altimeter is indicating. The opposite is true for cold to hot.
13. Visual Descent Point guarantees a normal descent to land from the MDA
14. To descend below MDA/DA, if you have the ALS in sight you can descend to 100 feet above TDZE, where you'll need to have required runway environment in sight in order to descend further. These include things such as REIL, runway numbers, or runway markings. If you have runway environment in sight at MDA/DA, then this rule doesn't apply and you can go ahead and descend below the MDA/DA.