This message was posted on behalf of Intel Corporation
Based on your description, your processor is behaving as expected.
"Now the processor has a base frequency of 2.6 and in turbo it is said to reach 3.5 but mine is way lower."
Bear in mind that Intel® Turbo Boost Technology is a way to automatically run the processor core faster than the noted frequency. This varying on this parameter will depend on the tasks and processes running, the processor will reach the frequency needed whenever the elements require it.
"Also the maximum temperature when rendering in premiere which takes 100% of the processor is 70 degrees and it feels odd for a processor working at 100% for 20 minutes to only reach 70 degrees on a laptop I think"
The maximum temperature for your processor is 100°C, so 70°C is just fine especially if it is under stress.
For further reference visit Frequently Asked Questions about Intel® Turbo Boost Technology.