Blank canvas, steel sided 40x60 pole barn. Thoughts on insulating, electrical, heating???

Don’t have time to read thru all the post so here goes. Same size pole barn, metal siding and roof. Bubble foil behind all then 2x6 rolled insulation, 1/2 osb ceiling walls, ceiling has not been insulated yet. One 80,000 btu oil furnace will keep it at 65 on 30 degree day very little running time when heating. One 275 gallon tank will last three years. Two 110 volt window ac units keep it 70 in the summer heat 85-95. Conduit electrical, outlets ever 8 ft 200 amp panel box I also have a 50 hp 3 phase Roto-Phase motor for any 3 phase machinery (converts single to 3 phase) put all this in myself. National Barn put the building up I did the rest even the 10x10 roll up insulated doors. Right now it’s about 29 degrees, I can turn on the heat and in fifteen minutes it’s 65 in there, furnace is a Rehm .45 gallons an hour but that would be continuous running which it dont. Some day I might insulate the ceiling lol
In 13 years it has never frozen inside with no heat on.