Good posts here, and an issue here for several years at my place.
I keep all my seeds and most food in glass jars, metal tins (like you can get popcorn or coffee in) and some of those small metal "garbage" cans w/lids found at Rural King.
If on a FLAT floor, certain filing cabinets are mouse proof...too bad mine was on a very crooked wooden floor for a bit :)
Clean clean clean, sweep sweep sweep, and move furniture/shelves/crates/etc, often...open and check drawers for signs of food hoarding or bedding.
Looks like you are already trying your best to seal things up!
Heres a story, it's sad so don't read if you love mice :(
I do love mice, but I can also be shifty and turn to hate mice when suffering from insomnia due to thier ruckus. I'm not a fan of snap or sticky traps, if I'm going to kill something I want it to be personal. I've tried "friendly" traps in the past but sadly have forgotten to check them quick enuf and thats a bad thought to live with. My brother came down to stay for a bit and while I was kinda just dealing with the mice thru non-violence, he wasn't having it.
So I opted for a bb gun. Red Ryder to be exact. We ziptied a small flashlight to the barrel for nite stalking and I also had a flashlight (e have no electric here). Thought this would be a quick way to do the dirty work.
My brother took the first shot around 11pm... well it sent the poor mouse flying off the shelf but he ran away - we were on him tho and found him in a corner, another shot, ran again under the wood stove, 2 more shots nearly point blank...he was hurt bad but managed to scurry under a dresser. Another shot, I was holding my flashlight right on him up close, he took the hit, still alive, albeit slightly different looking and such a horrible look in his little eyes staring right at me from only 1ft away, I took the knife I had in my hand and had to let out a grunt and finished him aggressively with a thrust to the neck as hard as I could up against the wall. Wow, super traumatic I'll remember that mouse forever. I feel so bad but it definitely improved human living conditions here as that mouse was getting very bold due to the slack I had been cutting him. I gave him a proper burial outside, a real trooper.
Get this tho- 2 days later what appeared to be a female and 3 young were dead in my makeshift sink that I happened to forget to fling outside (think stainless steel bucket with acouple inches of water in it) I think they might have killed themselves out of missing or possibly witnessing the death of thier male father/partner?? I think about them nearly every day, this was about a month ago...a stray mouse or 2 have come in since then but not nearly as bad as the one I ended up killing.
I do know that I never want to kill another mouse again, just gotta do better at living clean and kept!