I've been using all kinds of vinyl tile in rentals for many years.

I had a friend that was at the point of tiling his new shower and putting up kitchen backsplash when the inspector knocked on the door to snoop around.  

My initial thoughts are to spend money upgrading the kitchen and master bath; granite countertops, tile backsplash, maybe a pot filler over range, tile shower, extra windows?

The 2nd and 3rd floor needs rehab work including, - Full Painting Flooring (Vinyl/Linoleum)- Replace Kitchen cabinets- Renovate the Bathrooms (replace tiles)- Drop a wall and make a corridor- Electrical throughout My question is, do I need to apply for a permit for all of this work?

You've got asbestos in the walls but it can also be common in other places like acoustic ceiling tiles, popcorn ceilings, flooring (9"x9" tiles especially), ducts as mentioned above, and siding among other placesInsulation, or lack thereof.Soundproofing, or lack thereof. 

And what are your reasons for adding your kids to tile?

.- We designed the units for low maintenance (tile floors, only electric - no gas fixtures)- We had 9 parking spots for 6 units so we rented out the 2nd spots

Exactly....Take even a small bathroom remodel.....What type of tile is being installed?

Once I get the property, I will start ripping off carpet, and the tiles in the bathroom/kitchen, etc. 

If it's a rental, perhaps a shower pan and tiled walls?