Hi Huy,
First about treasure, I'll write detailed instructions even if I realised you already get treasure spawning.
You need to activate testingcheats (CTRL+Shift+C, then type testingcheatsenabled true then press enter) and then type buydebug. You need buydebug to buy chest in tomb objects in buy mode, but testingcheats are unlocking settings for treasure.
Hold CTRL+Shift and left click on treasure chest. You'll get many options, first you might want to Set Treasure Chest info - you set how many items will spawn and if it will be locked. I had no problems with setting the number, but haven't success in changing chest into being locked (maybe after saving and reloading game it will turn that way). After setting how many items will be in chest, repeat CTRL+Shift+left click on treasure chest and chose "Treasure Component" and you'll get to chose "one time" and "regular" treasure info, both option will lead you to the list of all possible things that can spawn in chest. Keep in mind that you can do the same with nectar racks so save chests for treasures.
From the list, money sign mean money bags, and (!!!) keep giving me valuable nectar - (!!!) gave me 94.124$ worth nectar, (!!) gave me around 49.000$ nectar, and (!) gave 24.000$ nectar.
Everything else will appear too, as soon as you set it, even in your home town, from tomb collection relics to specific keystones (which is really great if you want that collection soon, or want to enter some tombs without waiting for adventure).
This works at home(residential) and comunity lot.
Two things that doesn't really work that easily are respawning and changing settings. Even after saving game and going to main menu and back, chest doesn't respawn items - same as it works on vacation - while you're there, everything is static and treasure is not respawning. If you set treasure chest in your home (home lot, or somewhere in town) it will respawn only when your Sim goes to vacation. If you set it one time only, it will not respawn even then.
Changing settings is not working for me, if I set ancient coins, then change it to dry food, chest will still spawn ancient coins. But you can easily buy new one and set it to what you want.
About butler, if your Sim has him/her in relationship panel, get LTR Legendary host and invite him/her to the party, and then delete him/her. Butlers are bugged for many players, and it is likely any future butler you get in that saved file will behave strange. Maybe the best solution would be to save that household with or without lot to the bin, and move to fresh town.