- Poking holes in a plastic project box with a soldering iron isn't something you'd do in production, but it's fairly common when screwing around with a hobbyist project.<p>- Twisted-pair cable either requires either grounding one wire in the pair (in 100baseT) or fancy differential-signalling tricks. (in 1000baseT or HDMI)<p>- Sounds like the biggest problem was solder joint failure as a result of inadequate strain relief. In satellite design, where repair is, of course, impossible; the rule is to never use a solder joint as a mechanical connection. The component is secured to the frame, and the wire coming off the component is separately secured.<p>If you're not building a satellite, the method of accomplishing this is usually hot-glue, copious amounts of it, on everything. (As seen in cheap hand-assembled electronics. Expensive electronics are robot-assembled and use SMD components, which usually don't need strain relief unless you're doing something really exciting.)