You are welcome. Sorry to hear that you have had a bad experience with the IRS. How did they mistake the LLC for having 100 partners instead of 2 partners? Sounds as if you were able to get that matter squared away.
By default, unless elected to be taxed as a corporation, a multi-member LLC is considered a partnership.
Q1: My biggest concern is, would IRS seize partners' personal asset such as bank account when the LLC does not have enough property?
A1: In brief, yes.
Q2: If so, how fast are they?
A2: This question I am unable to definitively answer.
for All Owners
First, partners are personally liable for all business debts and obligations, including court judgments. This means that if the business itself can't pay a creditor, such as a supplier, lender, or landlord, the creditor can legally come after any partner's house, car, or other possessions.
There are a few exceptions to this personal liability. Some of the partners can have limited personal liability if the partnership is set up as a limited partnership. This is a partnership in which only the general partner, who runs the business, has personal liability, while the limited partners, who are basically passive investors, can lose no more than their stake in the partnership. Also, some states allow special limited liability partnerships (LLPs). More commonly, though, business people who are particularly concerned about personal liability choose to incorporate their business or operate as a limited liability company (LLC).
Hopefully the information that I have provided will help you. Respectively, a positive rating is appreciated.