The biggest problem for any partnership is not outlining each person's responsibilities in the beginning.

@John Cameron Its not worth it to Syndicate 5-10 units. unless the cost is high...You better off doing a partnership with fewer partners then having many to report back to.But you must follow the SEC Rules. 

I don't see how that will work honestly.I hear that you probably need a LLC if you a group of you, e.g. a partnership, is seeking financing to purchase a property. 

We created an LLC and partnership agreement over the past couple of weeks but now geared more towards preparing how to approach the bank.I have secured a 6-month internship that will be paying me roughly $3,500/month starting in June while my business partner will be starting his masters for data analytics.

To your second question, business organizations exist in the following formats...sole proprietor (can be llc, S-corp and still be considered such), partnership (can be llp), syndicate, registered corporation. 

When forming an investment partnership for the sake of purchasing multifamily investment properties, is it possible to include unaccredited investors? 

We frequently do partnerships like this. 

I have done both seller financing with as little as 5% down payment and have done JV partnerships with my partners bringing in a good portion of money and even being the guarantor on the loan.

It is up to the shareholders to determine if they want to take "partnership draws" AKA distributing the profits OR keeping the money in the company to buy more properties, increase reserves, etc.Operating agreement spells all this out so important to review that before setting up the partnership

My IRA/LLC’s Operating Agreement has a TON of language regarding what it can and can’t do because it’s owned by a qualified plan.I’m in the process of forming a partnership LLC with an individual and my IRA/LLC.