Question: Does that mean that come regular tax time I need to include whatever income I earned as an independent contractor on my 'normal' tax form, come tax time.
A: Yes.
No piece of income is taxed in isolation. You file one tax return, reporting all your income . As such, the answers to your other questions apply to your total combined income (both fire and uber).
Since this will be your first year with Uber income, estimated payments are essentially optional; since your regular withholding should meet the 100% rule
