To answer question #1 (assuming you are flying an airplane):
§61.57 (c)(1) states that:
Use of an airplane, powered-lift, helicopter, or airship for
maintaining instrument experience. Within the 6 calendar months
preceding the month of the flight, that person performed and logged at
least the following tasks and iterations in an airplane, powered-lift,
helicopter, or airship, as appropriate, for the instrument rating
privileges to be maintained in actual weather conditions, or under
simulated conditions using a view-limiting device that involves having
performed the following—
(i) Six instrument approaches.
(ii) Holding procedures and tasks.
(iii) Intercepting and tracking courses through the use of
navigational electronic systems.
As of Sept 1, to maintain instrument proficiency, you will be required to accomplish items i-iii in either an airplane under actual or simulated IMC (you must have at least passed the FAF and begun the final segment of the approach under these conditions for it to count) or have accomplished this in an approved simulator or FTD appropriate to the category and class of aircraft you seek currency in. See §61.57 (c)(2). Therefore in Sept, you would be required to accomplish at least 1 IAP in order to remain instrument proficient for that month. It is suggested at this point to accomplish the required 6 approaches, hold procedures and course tracking in Sept to avoid repeating this process often while still maintaining instrument currency, though this is not required to meed minimum instrument proficiency standards.
Question #2: see first paragraph of §61.57 (c)(1) - you must have accomplished tasks i-iii within 6 months of any IFR flight where you are acting as PIC. In scenario #2 you are never current as you have not accomplished tasks i-iii within 6 calendar months for any month shown. Assuming that you were instrument current in December of the previous year (items i-iii accomplished within that month), you still have a "grace period" to fly the approaches with a safety pilot starting in July of this year. If items i-iii of §61.57 (c)(1) are not accomplished by December of this year, an IPC will be required as of January 1 of next year to maintain instrument proficiency.
Item iii of §61.57 (c)(1) is a little bit of a contention, but if you are not flying contact or precision radar approaches only to maintain instrument proficiency, you will have used navigational electronic systems to fly these instrument approaches or fly the holding patterns with so item iii can be counted towards with the accomplishment of items i and ii.