It is worth noting that the section of the wire coming from the positive terminal of the battery to the first fuse is effectively unprotected. If this was ever too short, it could cause an electrical fire. For this reason, you should fit the first fuse for each electric circuit as close to the battery/power source as possible.
How I understand the second phase: if wire is too short, it could cause a fire.
How I understood the third phrase: we must make this wire as short as possible for safety reasons.
Either there is a mistake in the text, or I don't get the meaning of the expression.