You already have a number of my ideas....
So what size are these proposed cards?
I would like to see more than one of the following Bar, Bank, Store, Castle, Keep, Farm ect...
One of the issues I have with many of my tiles sets is the repetition in things.
Double sided tiles can be a good idea, until that moment you need both sides of the tile up for some reason or another.
More tiles ideas:
Trees and bushes, each tile looks different than the others...nothing like looking at a carbon copy forest. BLAH
Homes of various sizes and types.
Swamps.
Gear marker tiles. A set of small 1x1 tiles that have images of adventure gear. And each tile must look different than the other. A set of 6 or 8 should be perfect Why? I require a 'gear drop' for heroes entering combat, or they pay a combat dice penalty due to encumbrance. The gear marker is placed on an adjacent square. If a hero needs something from their gear they must be adjacent to the gear and spend an action to recover the item. When designing them keep in mind that each hero as a class will have different looking piles of stuff.
Dead man markers. Not just a skull and bones. A dead Ork, a dead Man, a dead Elf etc..... And lots of them. Each should be somewhat different than the other. "Oh look all the dead dudes look the same, now which one is the corpse we need to loot again guys?"
Wagons, carts, flying carpets, and Gnome {or Dwarf, I don't know your storyline} built steam powered land wagons.
City park. {lots of statues}
Furniture that is different than the Hero Quest furniture. Couch, loveseat, card table, potbelly stove.
I got more I am sure but the dogs are bugging me to pay attention to them.
So it is said that if you know your enemies and know yourself, you can win a hundred battles without a single loss.
If you only know yourself, but not your opponent, you may win or may lose.
If you know neither yourself nor your enemy, you will always endanger yourself.
~Sun Tsu The art of War~