Things to look out for while using LinkedIn:
Don't send 100 connection requests every day.
Avoid sourcing more than 250 contacts daily.
Keep the number of pending connection requests at a human-level.
In order to remove the pending requests on LinkedIn, take the following steps:
Go to 'my network' on the top
Click 'manage' in the invitation section
Choose the ones you want to remove and click 'withdraw' on the right.