"1.)It says STS payloads requires Shuttle fleet, does it require the expansion pack?"
Yes, you need the STS Expansion Pack v4.0.1.
"I tried moving the Bases from CONFIG/EARTH/STS to CONFIG/EARTH/BASE and every time I start up orbiter it wont work, there is nothing in the orbiter log that suggests why."
I don't know why you want to do this, but it doesn't work because Payloads looks for this in the CONFIG/EARTH/STS folder.
"and where would I find the KSC night texture?"
Sorry, I don't know of one. It's not needed to run Payloads.
Hope this helps,
zerofay32