Electronic – Unusual resistor symbol: resitor with Z overlaid

Looks like brown black silver gold black.

According to this web page, if the fourth band is gold or silver, the 5th band is temperature coefficient.

That makes this 0.1 ohm, 5%, 250 ppm/degree K, which makes perfect sense for something like an overcurrent sense shunt.

1. The three components above are Integrated Circuits, or more vulgarly chips. If you want to search them on Internet for each one, add the 'datasheet' word to the one in question (Can't see the numbers clearly, but they seem 4532, 4508, 4572).

2. All the other question you asked seem to be, to some extent, specific to a certain software that has been used to make these diagrams. If you don't know, try to know what software was used to do the job, and then get to its help/manual/documentation.