Happy to hear you're enjoying the game! And wow! 202 is the highest level I've seen anyone have so far (including me and my playtesters)! It didn't actually occur to me to test it out, which I'll definitely be doing from now on.
The "never breaking" resources is a bug I've tried to fix multiple times, but it looks I still didn't manage to. Gonna take another look at it.
The furnace staying at 100 might be intended. If you go to the top of the lighthouse you should see a counter to 10000. If you feed the furnace with 10k or more items, it becomes permanently lit. If you think that wasn't the case, please let me know!
The performance issue in City I haven't encountered before, can I ask if it became an issue immediately when you entered the level, or over time? Also, are you playing on the web version or downloadable?
Thank you for the feedback!