For me, USB 3.0 devices have been fully compatible with USB 2.0 computer ports once the proper drivers are installed. The USB device usually comes with the drivers on it or you download them from the manufacturer's website. USB 3.0 cords are constructed so the computer end of the cable is compatible with the contacts in a USB 2.0 port, a USB 3.0 port just has more contacts. Everything of course transfers at USB 2.0 speed.
Laptops are the bane of your existence when you own them. Buy new with all the latest options installed and hope their firmware and implementation are not buggy if newly released.
When newer, high speed port specs get adopted, find a buddy who desperately wants a laptop, sell your old one and buy a new one with the latest high speed interfaces.
What would be a simple slot fill on a desktop case is usually impossible on a laptop unless there was some expansion slot left open for future upgrade (rarely happens or the cards quit being available 6 months before you start looking for one) and as you found, the older, possibly usable slots get removed to save weight and room and the current ports are all low speed. It gets worse as they get thinner and lighter.
If your goal is higher speed backup, then the highest speed port on it will probably be your ethernet port with NAS or another computer being the targets.
eSATA is strictly an end device connection and not intended as a multiple device data bus like USB 3.0 so it's not likely you will find an eSATA to USB 3.0 converter.
The USB to ExpressCard Adapters listed in those links will still only run at USB 2.0 speed, its not worth the translation from USB 2.0 to ExpressCard to USB 3.0. The overhead will probably deliver far less than USB 2.0 speed. It's just better to load the proper drivers and plug the USB 3.0 cable into the USB 2.0 port.