The Lenovo ThinkPad X1 Carbon Gen 8, is not on the compatibility list for this docking station. You can use a universal Thunderbolt 3.0 docking station with this laptop, like this one: https://www.bestbuy.com/site/belkin-thunderbolt-3-docking-station/6343826.p?skuId=6343826

The Lenovo IdeaPad 3 14 Laptop, model number 81W000NGUS, ships with a 2CELL_35WH_INTERNAL, Lithium Polymer Battery, which within this configuration, has a battery life of up to 7 hours, depending on the work the device is performing.

That really will depend on the requirements and compatibility of the specific software you want to run. The Lenovo IdeaPad 3 15 laptop, model number 81WR000FUS, ships with Windows 10 S-Mode 64-bit Operating System. Windows 10 S-Mode provides added security by only allowing APPs available ( and therefore certified by Microsoft) at the Microsoft Store. If you don't need the added security or you need to install APPs not available at the Microsoft Store, you can switch to standard Windows 10 Home 64-bit Operating System, at no additional cost. We recommend you check with the specific game's software publisher's web sites for their compatibility with Windows 10 S-Mode 64-bit operating system and the minimum/recommended hardware requirements (Is a Graphics card required, the processor speed and the minimum required system RAM and the minimum available hard drive space) to run their program, then compare those requirements to this system's configuration. If you choose to switch out of S-Mode for Windows 10 Home, here is a link to instructions for switching from Windows 10 S-Mode to Windows 10 Home: https://support.microsoft.com/en-us/help/4456067/windows-10-switch-out-of-s-mode

No. The Intel Evo-Certified, Lenovo Yoga 7i 14 model number 82BH0006US, ships with 12GB Soldered DDR4-3200MHz RAM, Memory soldered to systemboard, no slots, dual-channel and is not upgradeable.