Check thoroughly for vacuum leaks, both with carb cleaner... Use a hose with one end held up to your ear and the other to probe.. checking all logical and illogical places a vacuum leak could be.
You can usually just "torque through" the cotter pin remnants. Or take a similar sized punch (if you can get in there) and drtive it out. But I usually just torque em off!
I agree if your goal is just a driver then this is not a bad choice if the price is right. (and as you point out that is a local thing). You want to get your head (and supplies) into electrical work; but as many will tell you, it looks worse than...
Yup burned. When you get back together need to make sure it's not running to lean due to tuning OR vacuum leaks. The further a cylindar is from the carb (throttle body) the greater the likleyhood of a lean condition. All engines have unequal...