At 0 your in positive, depends how heavy your foot is. 7+ is never reached unless you're running higher than stock boost about 14psi, in which case that gauge is useless anyway.
I tested my sender with my multi. and it checks out as functioning normally. As for my temp gauge it sits just slightly under half for me, 1/3 I would say which is normal, on a hotter day 30+ it sits very close to half and stays there.
Plenty of videos on YouTube with gauges for your reference anyway. Good luck.