Found my answer:An LLC that is not considered a separate entity for federal income tax purposes is taxed in the same way as a sole proprietor: the LLC’s income and expenses are reported as self-employment income on Schedule C of the member’s personal tax return.

I use it for my landscaping business but I opened one up as a sole proprietor for my real estate investment business. 

You can still deduct business expenses as a Sole Proprietor.

Definitely for RE I believe it's best to be an LLC vs. sole proprietor, as it sounds like you already know, and I'm being told now that the bar for when it makes sense to be treated as an S Corp for tax purposes is likely closer to $50K income, not well into the six figures, as many people will tell you.

However, you could us a "disregarded LLC" (a single member LLC that chooses to be taxed as a sole proprietor which means it doesn't file it's own tax return). 

For example I heard that healthcare might be a deductible expense for a sole proprietor/president of a business.

I can't see it being allocated to an expense account, and since you are claiming the profits on your personal income taxes (I am assuming Sole-Proprietor Schedule C or E), then it would not make sense for it to be a payment to shareholders -- since you should be the sole shareholder. 

Since SOLE-PROPRIETOR is still a legitimate business structure, it is possible to establish a 401K just using your own social security number.

Remember that you need to be either sole proprietor or SMLLC to hire kids and avoid the FICA taxes.If you have a partnership, parents needs to be partners to avoid FICA. 

The reason I’m thinking about this now is because I know the benefits you get from incorporating instead of doing business as, like a sole proprietor.