Friggin' awesome, brother,
to the forums. You've come to the right place.
As to your questions, the car should pull hard from as low as 1500-2000 rpm, you may have put crap gas (EU 95) in it, use 98 or 100+ race gas from Shell.
The clicking could simply be direct injection, these 2150 psi injectors are pretty loud, but a video would be nice.
Slow start means either a weak battery or, of it's only slow when warm or hot starting, you may have the known starter issue that many (including myself) addressed with an extra ground strap, see
https://www.camaro6.com/forums/showthread.php?t=586153 for details.
The red lettering on the valve cover is junk, it comes off on nearly every car. I'd repaint it with high temperature paint myself. Still have my valve covers as good as new, they were removed when installing the supercharger, but you're too far away to send them over, sorry.
You have the Tremec 6-speed trans, which was a great choice, change the oil often and don't use shitty gas, other than that, just enjoy this masterpiece
