I believe that is what makes this site different than others to hear all sides,  blunt and unsugar coated from those of us in the business so those who are not in the business can benefit from straightforward discussions. 

The internal structure is sound and supported by wood pillars, wood floor joists, and wood beams(unfortunately they are coated in lead-based paint).  

Use that to fill the gouges almost level with the existing plaster surface, then fill in the rest with a nice even skim coat.  

Here's what I gleaned as a summary of hardening tips for reducing turnover/maintenance costs:panasonic bath fans with timers in bathrooms4 coats of poly on wood floorsdouble door stopstile floors, showers vs surroundssingle lever shower valve vs. doublereplace toilets with steel parts/mechanicals whenever it starts to runKwikset smart keys (some debate over efficacy)door stoppers on all hingesremove pop-up drains and replace with commercial drains2' drain lines from sinks with an accessible clean outbuy a key cutter - maker for $50 on craigslistGranite tile counters - need a diamond polisher and tile sawUsed Fixed vs. friction shower rodsKeyed deadbolt and passage knob on outside doors to prevent accidental lockout5/8' fire core drywall - can't put a fist thru it and its fire-resistant1/4" board to back up towel rodspolyurethane cabinets under sink to pre seal and drain water to the floor2x4 base under cabinets to prevent particle board cabinets from failing where they meet the floorVinyl scrap under sink and up the back wallBest of luck!

Bank agreed, gave me $2500 back.closed the deal. place only needed to be cleaned + fresh coat of pain.

The only downside is that for the thicker vinyl plank (I don't use the really thin 2mm stuff) the prices are increasing because of it's popularity.I still generally use dark rental grade carpet in my bedrooms.

 #3 will differ depending on your locale, latitude, etc, but here in the sunny dry southwest, its basically as follows:  Roof coatings, Mini-Split HVAC units, the best windows you can afford (or glass block has a VERY high R-Value) and if you really want to go big, PV/Solar system.  

If it is in decent shape, it may simply be painted over with a proper primer and top coat.  

8) Is it the norm for the landlord to put a fresh coat of paint inside? 

We usually need two weeks for demo and installation of electrical and plumbing, then a week for inspection, a couple days for insulation, then inspection again and then about a week and a half for rocking, tape, 3 coats of mud, sanding and texture.