The streaks in your original posted images are almost certainly uneven development caused by much too short a development time. The highlights of the image (darkest areas in the negative) tend to show up very quickly (almost instantly with my Ilford paper and Dektol dev), but the shadow areas take longer, usually a full minute or more. Don't be afraid to leave it in for the full development time. Also, agitate by rocking the tray a couple of times every fifteen seconds or so. If the images are overexposed, shorten your exposure time or use a smaller pinhole.
You can also try diluting the developer. For instance, the standard Dektol mix is 1:1 water/developer stock. I use 5:1 (more water) for paper negatives. Increasing the dilution also tends to soften contrast, however. If you have serious low-contrast problems and you're using variable contrast paper, you can try adding a high-contrast VC printing filter in front of or (preferrably) behind the pinhole. This will, of course, increase your exposure time. Note that with VC papers, you'll get some weird contrast effects depending on the colors present in your subject if you don't filter.
What's the distance between your pinhole and the paper you're using for film? Mine is usually about six inches (150mm), and I use a .5mm diameter pinhole, exposing for 45-60 seconds in bright sunlight. Also, at that distance, with a small pinhole, the silver reflection shouldn't be a problem, but it can't hurt to paint everything flat black. Also, taping off seams, edges, corners, and anywhere else light might leak in is a very good idea.