Good questions and lots of good info in response; I will add my opinions.
Re tents, I am a fan of using a good 2 person tent (really a 1 person w/ extra room) with a great vestibule and a gear loft. Luxurious! But seriously, the extra weight is no biggie, and you can always split up tent components in your packing setup if you are picky about weight distribution, etc. The extra space comes in handy in so many ways (practically and mentally). There are so many good tent options on the market nowadays.
Re panniers/bags, it can be variable, but I usually leave some on the bike and put a couple in the tent vestibule so I can easily access if needed. My panniers are easily removable. Can vary based on weather, how well I packed, where I'm camping, etc. My advice would be to give yourself the option of taking stuff off the bike if circumstances warrant (and thus vestibules are awesome and indispensable IMO).
Yes, keep food and toiletries out of the tent, always.
Re stoves, I love my Trangia, but would not bring it on a cross country trip during the summer months. There are a number of areas in the West where alcohol stoves are prohibited due to wildfire concerns (lack of on/off capabilities and fuel spillage potential). This issue has been discussed in some other posts on this forum. I use my Trangia when/where allowed, but otherwise bring a basic, light weight canister stove to avoid the problem. Not an issue to fool around with given the wildfire crises facing the mountain West.
Happy planning....