In my quest to maximize how much money I make and minimize how much I pay Uncle Sam, I have started looking into setting up a Solo 401k for myself this year. My basic understanding of it is I can contribute a percentage of my net income (thinking it's 20%) of my side hustles into it. I am already maxing out my main jobs 401k, so everything would be considered an "employer contribution". A few questions I have:
1. Can I consider bank account bonus churning as income in this situation? --> I'm thinking yes since I have to pay taxes on it but wondering if anyone has done this before. Will run this one by my tax people later on as well.
2. I have a secondary job (adjunct instructor) that I get a reasonable sum from each year (~7k). I do not believe I am eligible for a 401k plan at this (need to double check), but would this be allowed to be considered as income for a Solo 401k? For this one, I have a W-2, so am considered an employee, so thinking not, but figured I would ask.
3. Is there a way to take advantage of a Solo 401k doing some sort of crazy financial jiu jitsu to effectively "contribute" in excess of the allowed 20%? Thinking along the lines of mega backdoor Roth stuff (my main employer doesn't allow non-roth after-tax contributions).