1. You can't record Git Analog via S/PDIF, what you get is Git Studio.
2. Git Analog would always be faster cause it skips the entire Kemper AD/DSP/DA chain.
3. Git Studio should be faster as well because it skips the entire DSP (Stomps, Stack, Effects) chain.
4. You don't need to fix this if you record DI only for the purpose of re-amping.
5. In your case I guess you want to mix Bass and Bass DI ... here you should align either by dragging the events accordingly or by using the Track Delay function (milliseconds) in Cubase.