This will likely be merged into one of the many Hlaalu towns we're making in TR, like Hlan Oek, so keep that in mind.

Review time!

Clean: Yes
Northmarker: Yes
Illegal To Sleep Here: Yes
Fits Exterior: Unclear. Most Hlaalu buildings have floorplans of approximately 2x3, and this interior does not appear to match any particular Hlaalu exterior building.
Ambient lighting: Good
Pathgrid: Yes, though there is no way for a Dunmer player character to pass between desk chair and table/bench in the vanilla engine - so minor adjustment to either pathgrid or furniture placement is required.

Floaters:

• None that I could find

Bleeders:

• flora_bc_fern_04 bleeds into the wall ever so slightly

Other:

• ingred_scrib_jelly_01 can be bled into the misc_de_bowl_01 it's in - it is a soft substance, so it would conform to whatever container it's placed in. I appreciate the effort you put in rotating this one, but in this case it's not necessary.
• potion_cyro_brandy_01 is perhaps mildly out of place and expensive for a poor interior, but it's only one of them so we'll say the occupant is saving it for a special occasion.
• There are two skill books in this int, which is on the high side. I would prefer having only one at the most, but it's not a deal breaker, more a thing to remember for future reference.
• flora_black_anther_02 is currently placed inside a misc_de_pot_glass_peach_02. As a general rule of thumb, do not place non-movable objects such as activators, statics and containers, inside objects that can be picked up, like this misc item pot. Either place the container flower in a static flowerpot or planter, or use an ingredient version such as T_IngFlor_BlackrosePetal_01. Alternatively create another instance of the misc object with a NoPickup script on it.
• In general, this interior contains a little too many large light sources. I would replace most of the lantens with 128 radius versions and remove one of the candles on the table. The 'green light' bug is sometimes unavoidable, but in this case I'd move the lantarns away from the walls a little by positioning the ropes and lanterns so they hang off the wooden rafters and a little away from the walls. There's no strict need for intricacy there, and it's generally alright to just bleed the end of the rope into the bottom of the wood. Lower radius lights also help mitigate lighting issues.
• Red lanterns: like others have said in this thread, these are used rather rarely - a total of 12 times in the vanilla game, and almost all of them in Morag Tong bases. If you want colored lights, blue and green are more commonly used and more acceptable.

Misc notes (not errors):

• Excellent execution on the rotation of items when placed on de_p furniture.
• Good judgement on bleeding the crab meat, though I'd prefer if it weren't lying out in the open on a bookshelf but on a plate or tray. You could also consider having fewer of these items right next to each other, as it's more typical to have one, two or at most three of them in an int, judging by vanilla ints. Vanilla has a tendency of putting ingredients on little papers, which you can consider in the future. Some, like the ingred_ash_yam_01 and ingred_corkbulb_root_01, don't need this, but ingred_coprinus_01 might benefit from it.
• I like the bread basket
• Sacks are properly bled
• I have absolutely no idea how there are two instances of misc_com_plate_07 stacked on top of the other in the CS (with one floating, to boot) but six of them stacked neatly once you check them out in game. A true mystery. It works, though, so that's good. I checked in TESAME and there is indeed data for six instances of the plate in this file. Phantom plates!
• Good placement on sc_paper plain - this is a common one to get wrong, and deftly you avoided this trap.
• Good positioning on the rugs
• Good use of loaddoors / load doorjambs
• Like I mentioned before, I like the verticality of the main room, and the construction here shows skill and attention to detail - good job. You didn't make it easy for yourself, but execution of this section, as far as I can see, is flawless. I commend you for taking the plunge into Tamriel_Data and using the appropriate pieces.

Conclusion:
There are very few defects in this showcase, and you've shown great attention to detail with placement and rotation. The verticality to the main room is great, and the use of Tamriel_Data pieces entirely appropriate.
The few things I mentioned in the 'others' section are mostly nitpicking on my part. All in all, there are seven or eight edits I'd make before I would call this ready-to-merge, if it were a TR interior claim, and stylistically it's great (apart from the red lanterns which have been discussed).
Considering you've already shown you respond to feedback promptly and positively, and have already updated the showcase based on Dillonn's suggestions, I'm confident you'll make a fine addition to our little community of modders.

So, I'm going to go ahead and promote you to interiors developer. Welcome to the team! Be sure to join us on Discord if you haven't already, it's where the bulk of project discussion happens these days, and you'll get some fancy badges over there to show you're a dev now.

I plan to have a look at your quest showcase at some point in the not-too-distant future as well but currently I don't have the time, apologies.

edit: uploaded reviewed file, in case we can use it in Hlaalu lands.