They look great (the technology has advance so much that people think they are real hardwood), they are very resilient, they are easy to install and maintain, they are waterproof (I had laminate in one rental and so had to change the entire flooring as it got ruin after a smal water accident; on the other hand, I install LVP in kitchens and bathrooms and never had an issue), etc. 

Specifically, do I need a permit to replace carpet/vinyl flooring with hardwood or a bathroom renovation with no structural updates ie ripping everything out and building back up with existing layoutI have done this in my primary residences but I've never done this on a rental property and can't find any documentation on the baltimore county website on whether I need a permit for these or not.

Large tile and or grey-toned hardwood/ laminate floors. 

On solid hardwood I'd try it in a heartbeat. 

I only use porcelain, but the big box stores run good sprecials on cheap ceramic, if it happens to be the look and durability you want.There's a local discount wood flloor place that sells prefinished hard wood flooring with good selection and good prices, but raw hardwoods, I go direct to the mill (which would only be for top of the line, to pay for all the finishing when pre-finished is so easy.)Some of these guys, I can call and order and I'll get just whay I want delevered.

Also I'm a GC, licensed builder, have 16 full time construction employees and 50+ independent subs and have my own store where I sell cabinets, tile, carpet, hardwood, vinyl to contractors and house flippers.

Looks to be original hardwood floors in good shape.

If there's hardwood or laminate, you're probably looking at prying that up as well to replace some of the soaked subfloor underneath.

Our work consisted mainly of repainting the whole place, inside and out, which included replacing a fair amount of the trim boards on the exterior, installing new copper gutters and flashings, a few minor repairs to the slate roof (no leaks), a new driveway and garage floor, new garage flat rubber roof, renovating 2 full bathrooms that we used a lot of pretty expensive tile in, all floors except the sunroom had hardwood floors that were sanded and refinished, the sunroom had a travertine floor installed.

New carpet or adding hardwood floors throughout. 2.