I'm a volunteer board member & engineer (with only a little helpful exposure to fire-separation issues) doing what I can to assist with maintenance problems at an aging (1974) condo facility in Honolulu.
At hand is the need to replace six or seven ragged, rusty steel & wood doors in our common area. Some have tags that are legible, others don't, but I believe this matters not, because few if any match with what is shown in original plans. Fire inspector's best advice was to follow those plans, but doing so led to more apparent conflicts and perhaps 1974-vintage fraud by the developer (who went out of biz as a partial result of problems with this complex). We'd rather spend our thin budget on over-rated doors than on getting a professional designer's input on these questions, but even doing THAT takes some knowledge. The engineer in me wants this to get done with at least some semblance of code-adherence, even if DIY. So here are my door-replacement questions:
Tower lobby common area:
Large glass storefront doors comprise the main lobby-level entry - unrated, of course. These don't need replacement (for maintenance reasons, at least). One mystery is that this door-space is shown in plans as "Open": a simple cased opening of 8' width. Office, laundry, and dwelling units are also present on this (ground) level. But the end-of-corridor (back) door , and side-door  (both leading more or less directly outside) are shown in door schedule as 90-min doors. No security would be possible without those glass storefront main doors, so I suspect they were left uninstalled until the certificate of occupancy was issued. But even if that's true, I don't understand why a large cased opening leading into the lobby would have been OK, while other doors to/from same lobby carried 90-minute ratings. I believe all walls in this area are reinforced concrete.
Tower laundry - exit to parking area:
This gyp-core wood door carries a 90-minute tag and was rated 90 minutes per door schedule, but has 2'x2' louvers installed in the *top* half, which I believe renders it unrated (louvers are to be installed on bottom half?) Need this door be rated to begin with? Do the top-half louvers indeed condemn it to have no real rating, then?
Tower mechanical room:
Plans called for this paired set to be 90-minute rated. Actual doors may or may not have visible tags, but are louvered far past 24" square, which I understand to be the maximum allowable (fusible) louver size for a rated door. This room exits to a parking garage, and includes gas water heaters, but is not designed for occupancy. Walls are reinforced-concrete, perhaps with CMU in some locations, if that matters.
Low-rise mechanical room:
Three doors in this area. Door schedule shows NO rating for any. These include the "boiler" room (again, gas heaters) the "storage" room (pool equipment and storage). Likewise, no rating is shown for the third room in this area, a paired set that serves a maintenance room. None of these rooms are designed for occupancy. All exit to a facility driveway. If it matters, walls are either CMU or reinforced concrete (I would have to visit and check).
Is this a simple set of questions for an NFPA-conversant A/E, or are there lots of nuances?
Let me know if I need to provide any other details to make the setting clear.