Covers are available, I purchased mine on Ebay. I do not experience interference problems unless I am close to a power center, or the occasional fenceless dog system. When I am almost over the wires to the fenceless dog line the T2 experiences feedback. But that is a minor problem. Headphones are a matter of choice. I happen to like the single earphone DetectorPro Rattler, but also on occasion use the headphones that came with my Garrett detector that the T2 replaced. They work great and have excellent sensitivity. The T2 needs to be re-set after you turn it off. The whole process is simple and takes less than 30 seconds. Once you get used to it you will find that you will start out with the same one to three settings that you will become familiar with. And once you have those turning the machine on, setting it up and starting your hunting will take all of 10 seconds or less. The only issue I have with my T2 is that I get feed back when I get close to some other detectors. Not all. One friend I hunt with uses a White's DFX. I can stand next to him and have no issues. My other hunting buddy uses a Fisher F-75----which is very similar to a T2----I can't be closer than about five paces from him otherwise my T2 gives off a lot of feedback. But I adjust and have no problems.
Good luck. The bottom line is the T2 is, hands down, the best detector I have ever used. If you get one, you will come to love it.