Making a few changes in an existing 4-gang switch box, I notice the original electrician did some things that seem a little funky. The various neutral and hot wires are just twisted together with a crimp ring and taped, but no wirenut. I can easily, and will, add wirenuts. But ... there is a pigtail coming from the bundle of hots, and it goes to two different switches, with a little insulation stripped off where it's screwed to the first switch, and then the stripped end screwed to the second switch in the usual fashion. I'd rather leave these two switches alone, as they have nothing to do with the changes I'm making (to one of the other two switches). Is this ok ? This work will not be inspected, but I want to do the right thing.
There's no problem with the wiring methods you've described. Using a single wire, reduces the number of wires in a slice. This can come in handy when trying to reduce the number of wires in a twist on wire connector.