Give it a go, it's really rewarding
You basically did the right thing in your method. Looks like you've worked out how much effect tightening a spoke 1/2 turn can make and you have also understood that doing the neighbouring spokes takes the pressure off the single spoke. You can use the brake caliper as a guide for centring the wheel. The frame is symmetrical so you can put the wheel in the other way round to check if it is offset at all.
The pinging that you hear is where the spoke is twisted, i.e. you turned the nipple round but it didn't turn all the way on the spoke thread, it just twisted the spoke round a bit. You always get this to some degree, but it's worse when the nipple is a bit tight on an old spoke. When the wheel is true, lean your weight on the bike and roll it round one or two revolutions, then spin it and check the trueness - then give it a final tweak. I love that pinging sound on a brand new wheel!