Everything on my bike is secured with a mixture of anti tamper screws, which are full of mud and one needs a special tool to get my wheels off, they wont even get the pesky anodised dust caps as they are the Richbrook spinning type, special tool required. I tested the wheel security recently when I mislaid the sodding special tool, the only way that I could undo the thing was hammer a piece of hardwood into the hole and turn that with molegrips. I reuse old brake cables as security cables, with swaged ends, they are light and very strong and many know if one does not have the correct cable snips what a pain it is to gnaw through brake cables with normal wire snips.
With what I have done, I am banking on a potential thief will not be carrying special tools beyond a set of allen keys and I do when I park the thing make sure it is in view of one of the many cctv cameras we have in this country. I don't like them, but if they have a use in preventing crime as the people who want them say, then my bike should be safe.
As to the ride to college, it is mixed terrain, about half of it is main road the rest, muddy tracks through woods, up hill and down dale, one needs a good bike for that, that is why I built it and the bike is panniered up, as I have to carry my macbook into college as all my work is on it, a laptop pannier on one side, and a normal pannier on the other for my tools. As for mud and salt water, the bike is protected with ACF50, fantastic stuff many motorcyclists use to protect their machines from the enviroment.
I am banking my security on the fact that it will be a timely challenge to a casual thief, anything that I do that increases the time to get caught is worth it, for if someone is caught tampering with my bike, I will push for them to feel the full weight of the law, as theft of cycle parts or cycle is theft regardless of what it is, theft is crime and I for one from past experiences want to rid the streets of crime. I don't particularly like the police from again past experiences, but I will help them do their job, even insist they do their job.
Visualise the local newspaper article about cycles being stolen or stripped parked in a cctv'd cycle park in plain view of a central police station, won't look good would it.