Premise:
"(Many online sites just plain stiff their clients for no reason.)"
Hypothesis: All websites pay every client.

no

Premise:
"On the east coast in Terengganu and Kelantan, the weaving and metalwork still practiced today trace their origins to this early colonization."
Hypothesis: The weaving there is known for being very high quality.

it is not possible to tell

Premise:
"It is expected that one SCR system requires about 21 months of total effort for planning, engineering, installation, and start-up."
Hypothesis: There are 4 different steps in the SCR system installation process.
yes