Land is so cheap that if you do end up buying a large tract taxes are really cheap and you could build your own portfolio of land in areas you desire. - Double closings/Assignments - As the land market is getting saturated with other investors.

My situation is that I wonder if I can use being a real estate agent as a strategy to save on taxes by creating a solo 401k.

If you have been working on it but not listed anywhere, you can't deduct any expenses until next tax cycle.Also, I would highly suggest you get yourself a CPA that can help you.

As far as taxing goes.

A $500k place renting for $3,500 but $500k at 6% is $3,000, add $100 for insurance and $300 for property taxes and you’re offering to buy the place they are renting to you for $3500 for a $100 less than the rent. 

Sarah's a qualified Accountant and has always dealt with our tax affairs, in the US and in the UK, so it makes total sense for us to take back control...

Also, for the taxes did you have to file state tax returns in all the states where there are mobile home parks that is for the ODC fund?

I am not opposed to flipping, but I need to educate myself on the tax implications first.

No property taxes. 

For the life of me I can’t really find a property to flip locally but the ones I’ve bought and held for 2 years have appreciated significantly and if I was to sell some of them now after all taxes, commissions and expenses were paid I’d probably profit about $65,000-$85,000 on the 2 year properties.