Yes it certainly sounds like your car needs a tune up which will improve it alot more then you would think. Beru seems to be a good brand for the leads generic plugs seem to work well, some people swear but the bosch platinum tho
With the heat problem is sounds like your hot water valve in the engine bay is not shutting off and due to the age of the cars some of the vents dont shut off properly which means air coming in all the time and with the hot water still flowing = hot air.
The valve seems to be fairly expensive new so all i did on mine is pushed it so that it was off and then removed and pluged the vacume lines, eventually i plan to replace it with a simple electric open close solinoid from say a garden watering system and put a switch inside.
With the heat problem is sounds like your hot water valve in the engine bay is not shutting off and due to the age of the cars some of the vents dont shut off properly which means air coming in all the time and with the hot water still flowing = hot air.
The valve seems to be fairly expensive new so all i did on mine is pushed it so that it was off and then removed and pluged the vacume lines, eventually i plan to replace it with a simple electric open close solinoid from say a garden watering system and put a switch inside.
