Tin* wherever it says tile. Oops.We are using backsplash from American Tin Ceilings

Just a pic of the more finished other side of the room (need to paint the doors) for enjoyment.

not a pro but for #1 I would think you would want to first install the bracket or cleat for the open shelves, then put up the tin BS - (usually the shelves mount on to a bracket)

for removing the pain from the hood #4 - I googled removing paint from stainless steel and this came up (I would test on a small inconspicous spot first)

Apply turpentine to a corner of a clean, soft cloth. Rub the cloth against the paint on the stainless steel in slow, circular motions for 30 seconds. Remove the cloth, and inspect the stainless steel. If the paint has not started dissolving, repeat the procedure with additional turpentine on another clean corner of the cloth.

Thanks for the turpentine tip! I also think what you say about installing bracket for the floating shelves before the backsplash makes sense.
The hood does vent outside. The cabinet trim will not be glue on, but the tin backsplash is. I think you’d need to see the listing photo which I’m including. We could not afford a $20k kitchen reno with new cabinets and I personally see nothing wrong with the refinishing & paint job we have done. I stand by my design decisions & I’m only asking for advice regarding the order in which to perform certain tasks which must be done.

Old countertops were like 90s laminate that were all damaged, never felt clean, sink was a SS double and not deep, basic faucet— terrible functionality. The relief that the counter/sink/faucet upgrade has brought be is substantial. That’s where we spent the money. Everything else is smaller scale upgrades and that is just fine with us.

Can anyone help with the last 2 dilemmas?

1.) Caulk between wall & backsplash before or after I install tiles?
2.) decorative trim around cabinets before or after I install tiles?

" 1.) Caulk between wall & backsplash before or after I install tiles? "

You have a backsplash. That 5" riser is your backsplash. If your intent was to tile that rise should have never been installed. I would paint the wall now and forgo the "tin" glue on tiles.

" 2.) decorative trim around cabinets before or after I install tiles? "

See above.

I know what a 4in backsplash is. We are installing the tin, like the following attached photos , it’s much like a wallpaper and I don’t expect it to perform like ceramic tiles would. I do need to know which order to do things in. If you don’t feel like helping me and would rather criticize me, cool. Hopefully someone else can answer the remaining questions for me.