In addition, I expect to have a positive cash flow on this property for $350 per month, giving me a good cash-on-cash return as well on that $20K.

from my point of view if your an individual and not partnering with folks who ever is going to sue you is going to name you personally.. this is where you need good insurance to take up your defense as your first line of defense.whether they have the right to sue you is immaterial.. or whether they will prevail is immaterial.. if your operating as a group or partnership and have clean records this can limit your exposure to your ownership.other than that  retirement accounts should be maxed out they basically cant be touched... certain trusts.but just LLC labyrinths like you mention.. those are not going to do it for most or.. you will spend a ton of dough fighting to make the position they can't sue you. when suits happen everyone is named .. that's when you need good insurance to handle your defense.

Currently I am aggressively establishing acquisition position to begin developing buy-and-hold portfolio consisting of residential multifamily (3-4 unit) and commercial multifamily (5-20 unit). 

I'm actually a big fan, and as mentioned above, have mostly very positive experiences.

I had looked into it in the past and there was a time period that needed to pass as well as an equity position beyond 20% that the mortgage company wanted me to have reached (I believe it was 25%) for PMI to drop.

Combine that with a couple other positive financial actions and you'll climb up. 

If you have positive personal experiences with any, please relate that and let me know what you liked about working with them. 

Another congrats Account Closed that you should find a way to share your story with young people who could benefit from a positive role model.

I should have mentioned the tax benefits of seller financing but I am not sure if that alone would have won him over.Thus far, I have concluded that seller financing for newbies might be a good starting point to get our feet wet especially in my position.

This is a completely selfish question but maybe the conversation will help others in the future that are in my position.