I like that last post, it makes sense. To answer your question, however, "How do you know when your engine is going bad?", well, it is easy, When your engine starts farting, belching, running rough, providing no power, and smelling bad, then it is either the victim of sudden sabotage, or has merely worn out. It takes YEARS for an angine to actually "go bad" when looked after properly. I mean, my 1981 GMC van has taken our band across the country on our tours on the original engine, and while the cam certainly has a flattened lobe, the unit still gets us around with little argument. To make a long story short, engines are made of metal, and metal is tough. All you need to do is make sure it gets the proper lubrication and attention. As said above, start the damn thing and let it run twice a month or so when in storage. The seals will remain fresh that way. But as far as wear goes, you could let a car stand for 50 years or let it stand overnight, a cold start is a cold start, and is hard on an engine. I know a lot of people hate oil additives, but I found one that I actually had to stop using on customers' engines (I am an OPE Technician) because it was costing me money in that they would go thrice the amount of time before having me service their equipment on a rotation. It is called "Power-up", and I really can't tell you much more than that the stuff works VERY well, and I will use it in my OWN machines forever. I would never put it in a fresh engine though, I guarantee the stuff is so slick that it would actually prevent the proper seating of piston rings in a fresh rebuild!
Anyway, I guess what i am getting at is that you shouldn't be afraid to use your vehicle after storage. Just go out there and fire itup once in a while, and no probs. The comes spring, she'll be ready to rumble.