#3: Can I renew my flight instructor certificate with my military Instructor Pilot check ride (instead of doing the online renewal course or other methods)? Yes, but maybe not if it's already expired (we'll have to see the job guide). Here is the applicable text from the Final Rule:

Additionally, we have further revised Sec. 61.197(a)(2)(iv) by providing an alternative procedure for current U.S. military instructor pilots and current U.S. military pilot examiners who hold FAA flight instructor certificates to renew their flight instructor certificate and ratings. This provision will require current U.S. military instructor pilots and current U.S. military pilot examiners to have completed an official U.S. Armed Forces military instructor pilot or military pilot examiner proficiency check within the preceding twelve calendar months as an alternative method for renewing their flight instructor certificate and ratings.

The new 61.197 words support that:

61.197 Renewal requirements for flight instructor certification.

(a) A person who holds a flight instructor certificate that has not expired may renew that flight instructor certificate by—

(2) Submitting a completed and signed application with the FAA and satisfactorily completing one of the following renewal requirements—

(i) A record of training students showing that, during the preceding 24 calendar months, the flight instructor has endorsed at least 5 students for a practical test for a certificate or rating and at least 80 percent of those students passed that test on the first attempt.

(ii) A record showing that. within the preceding 24 calendar months, the flight instructor has served as a company check pilot, chief flight instructor, company check airman, or flight instructor in a part 121 or part 135 operation, or in a position involving the regular evaluation of pilots.

(iii) A graduation certificate showing that, within the preceding 3 calendar months, the person has successfully completed an approved flight instructor refresher course consisting of ground training or flight training, or a combination of both.

(iv) A record showing that, within the preceding 12 months from the month of application, the flight instructor passed an official U.S. Armed Forces military instructor pilot proficiency check.

But here's the new words from 61.199 about expired certificates:

61.199 Reinstatement requirements of an expired flight instructor certificate.

(a)Flight instructor certificates.The holder of an expired flight instructor certificate who has not complied with the flight instructor renewal requirements of §61.197 may reinstate that flight instructor certificate and ratings by filing a completed and signed application with the FAA and satisfactorily completing one of the following reinstatement requirements:

(1)A flight instructor certification practical test, as prescribed by §61.183(h), for one of the ratings held on the expired flight instructor certificate.

(2)A flight instructor certification practical test for an additional rating.