I've done a lot of road miles on my mtb over winter and my tyres are definitely looking a little worse for wear as a result (hence buying a road bike for that stuff now!). But 5 miles each way to a trail? Wouldn't worry about that at all, in fact I do that most rides when I head up to my local trails.
In other news, finally got round to cleaning my chain so I could see whether my quick link is actually broken or not (it was filthy
). It seems to be bent on one side. Gonna head to my new LBS and get them to take a look and get a new quick link, halfrauds is out of stock.