The tip guard will reduce the likelihood of kickback from tip contact, but not 'pushback', cuts, etc. It does not make the chainsaw 'safe'.
If most of your cutting is bucking firewood to length, and your bar is long enough to cut through in a single pass, the tip guard will be OK. As noted, it can get in the way in some circumstances, or prevent you from making other types of cuts, but if you aren't making plunge cuts or cutting larger diameter trees, it will be OK, especially if you feel more comfortable starting out with it.
The other device could really get tangled in things, but is not a new idea. You will see other versions of it that people tried if you look back at some of the old photos of chainsaws.
Philbert