Snakes co-habbed can get very stressed, so maybe that's part of his attitude. Most corn snakes make really good pets, this one might need some patience for a while, but nothing too bad, I bet.
People get scared off easily by snakes that are less docile, then the feisty one never gets handled to learn any different. Good on you for taking this one in.
I've kept (also bred & raised) many corns for years, & currently have 5. As already noted, much cooler temps.- mine don't use their UTH (low to mid 80's) much even in the winter- ambient room temperatures are 70* (winter), & up to 80* in summer (during which I turn off their UTH for a bit). If you like your home cooler at night, even 68* shouldn't be a problem, as long as the ambient is warmer (70* or above) by day. My oldest corn currently is 21 years old.
Adults are 4.5-5.5' mostly- the bigger ones do well in 40 gal. breeder tanks with screen tops- good ventilation. They'll enjoy & use a humid hide- substrate doesn't need to hold humidity- I use a mix of Carefresh (hygroscopic!) & my own clean shredded paper, over a single layer of paper towel (makes it easier to remove & change). They like hides & may also enjoy basking on branches wedged into their cage (diagonally is what I do, crossing over in the middle of cage), either with or without a very dim warming light.
Hatchlings are fed at least once a week, but adults do well when fed about every 10 days- a little less or a little more is just fine. Adult mice of appropriate size. Perfect schedule isn't needed either. They're "forgiving" snakes, pretty & usually docile. This one sounds mostly stressed & probably scared from too little or awkward handling.
Your 10 gal. tank is too small for anything other than very temporary. A 30 gal+ would be a better fit, depending on size. The heat (UTH) should be at one end/corner- don't try to warm the whole tank.![]()