How do I get BTC out of my Multibit wallet? I have BTC in an old Multibit wallet.  Multibit is no longer support and the problem is you cannot set TX fees.  The standard fees are too low given the current state of the network.  What can I do to get my BTC out?  Is there another software wallet that will let me import my Multibit key?  

Also, I tried to send via Multibit a few days ago, but it's not showing up on blockchain.info or blockexplorer.com.  If I do import my private key to another software or online wallet, will it mess anything up being that there is a pending send tx in my Multibit wallet?
You will need to move your coins to something like Electrum. Give these tutorials a try perhaps: 


https://www.youtube.com/watch?v=E-KcY6KUVnY
https://www.youtube.com/watch?v=LaijbTcxsv8