Good job. Now think about taking a bit of the savings, and invest in a non contact voltage tester. They are found at Home Depot and Lowes starting at about $10. They detect voltage in an outlet or wire, just by touching the outside jacket of the wire, or sticking the tip into the outlet. It's a great way to confirm that you have found the right breaker, and properly killed the power whatever you are repairing. If you do use one, ALWAYS check it on a known hot circuit before you start checking your work. When it comes to loose outlets, screws can be an issue, but more commonly, it the fact that the "ears" on the top and bottom of the mounting strap are just floating, not sitting firmly on the wall. The cure for this is a stack of #8 flat washers, sandwiched between the box and the strap. This can take a floppy outlet and make it rock solid.