don't use the billion mile car that has been in more than one front end collision as teh example of how most cars react to not having the front sway bar on. lol
justin is right. it all depends on what YOU want to get out of the car and what you would like to live with. personally, i never use air conditioning, i have had it in several cars, just don't like it. so it comes out of any car i want to make fast. the same is true of so many other parts. as justin mentioned, it is about 50lbs you can lose.
removing the front sway bar will allow for more body roll when you turn and decrease the ability of the car to turn if you are running hard around town and trying to turn really hard. so if you are more interested in handling than straight line performance, leave it on. taking it off will take weight off the nose of the car, allow the front suspension to release better and transfer weight, and as long as you have good shocks you won't really notice much of a difference when doing normal around town adn highway driving. the front sway bar and associated hardware is somewhere around a 14lbs weight reduction
manual steering is a fine conversion as long as you understand that you won't be able to trun as fast. the car will still be capable of turning just as sharp, but you will have to move the steering wheel further with a manual steering box to get it done. converting from power to manual steering by installing a proper manual box will save you about 37lbs and take about .25hp of drag off the engine. lol
the smog equipment is an easy removal, you will fail a visual inspection in NJ without it if you care. if you remove everything properly you can drop about 17lbs.
as has been stated before. it is all about what your goals are and what you are willing to live with. personally, i don't need a whole lot of creature comforts in a car, i would rather be fast
