They would also be the best to talk with about corporate filing. 

@David Zheng"Salary" you pay yourself from a sole proprietorship or disregarded entity is just a non-deductible owner distribution.If you need earned income for Solo 401k, IRAs, etc, might be best to set up a Corp or LLC PM company and elect S status as @Ashish Acharya mentioned. 

Hi Team,I searched several keywords across BP and couldn't find an answer to these questions.I have several friends and family members who want to invest along with me as an LP in Syndication Deals.1) How should I structure it so that 1 company is investing as an LP (either an S-Corp or LLC), and other friends/family members are investing in my S-Corp/LLC?

A sole proprietor or corporation... 

A sole proprietor or corporation... lmk what are your PAIN POINTS that are on your to do list that you wish you pass over to a nerd like me LOL To take care of it all behind the scenes while you get to do what love to do most !!

Thats the part I don't really understand.You would sign some sort of agreement, called a guaranty, that if the LLC, or the corporate entity doesn't pay, I will personally pay it.

All income would go to the management company directly and it would cover the expenses.Would this blow up the corporate veil?

It's not making you money unless the lease also protects you corporate wide and in receivorship.  

Disclaimer: My experience with all this is corporate non-realestate world.

Also, you can only get 30 year notes in your personal name, when you go corporate you will need commercial loans, which are more expensive and usually 5 year ARMs.2.