About wall/floor, what about an option to "simply" remove all wall tiles, a toggle, so players can decide if they want "pretty" or "obvious". The wall tiles could then be nothing but a black empty tile.
Something else, i like the new looting system, but it's annoying to have the popup each time i click on a tile with a loot, telling me i need to be on adjacente tile to grab it.
About Action Points, maybe look at Vigilantes (Timeslip Softworks), Templar Battleforce (Trese Brothers), and other games with Action Points done differently (i mean different from Fallout or Xenonauts).
Maybe instead of having only a perk from Reaction to get 1 more action, do a 3 actions for all. It could be walk shot walk / shot walk shot / run shot / run walk / but also shot with special tricks / crawl / rest and heal / ambush / etc